Case study of a floor-cleaning robot
NASA Astrophysics Data System (ADS)
Branch, Allan C.
1998-01-01
Developing the technologies suitable of ra high level robotic application such as cleaning a floor has proved extremely difficult. Developing the robot mobility technology has been a stumbling block and developing and integrating the applications technology to the machine and the mobility technology has also been a difficult stage in this quest, but doing so in a cost effective and realistic manner suitable for the market place and to compete with humans and manually operated machines has been the most difficult of all. This paper describes one of these quests spanning a 14 year period and resulting in what is hoped will be the world's first commercially manufactured household robot vacuum cleaner.
Three Dimensional Inverse Synthetic Aperture Radar Imaging
1995-12-01
unfortunately produces a blurred image. To correct this problem, a deblurring filter must be applied to the data. It is preferred in some applications to...when the pulse is an impulse in time. So in order to get a high degree of downrange resolution directly it would be necessary to transmit the entire...bandwidth of frequencies simultaneously such as in an Impulse Radar. This would prove to be extremely difficult if not impossible. Luckily, the same
Exact simulation of max-stable processes.
Dombry, Clément; Engelke, Sebastian; Oesting, Marco
2016-06-01
Max-stable processes play an important role as models for spatial extreme events. Their complex structure as the pointwise maximum over an infinite number of random functions makes their simulation difficult. Algorithms based on finite approximations are often inexact and computationally inefficient. We present a new algorithm for exact simulation of a max-stable process at a finite number of locations. It relies on the idea of simulating only the extremal functions, that is, those functions in the construction of a max-stable process that effectively contribute to the pointwise maximum. We further generalize the algorithm by Dieker & Mikosch (2015) for Brown-Resnick processes and use it for exact simulation via the spectral measure. We study the complexity of both algorithms, prove that our new approach via extremal functions is always more efficient, and provide closed-form expressions for their implementation that cover most popular models for max-stable processes and multivariate extreme value distributions. For simulation on dense grids, an adaptive design of the extremal function algorithm is proposed.
Low Bandwidth Robust Controllers for Flight
NASA Technical Reports Server (NTRS)
Biezad, Daniel J.; Chou, Hwei-Lan
1993-01-01
Through throttle manipulations, engine thrust can be used for emergency flight control for multi-engine aircraft. Previous study by NASA Dryden has shown the use of throttles for emergency flight control to be very difficult. In general, manual fly-by-throttle is extremely difficult - with landing almost impossible, but control augmentation makes runway landings feasible. Flight path control using throttles-only to achieve safe emergency landing for a large jet transport airplane, Boeing 720, was investigated using Quantitative Feedback Theory (QFT). Results were compared to an augmented control developed in a previous simulation study. The control augmentation corrected the unsatisfactory open-loop characteristics by increasing system bandwidth and damping, but increasing the control bandwidth substantially proved very difficult. The augmented pitch control is robust under no or moderate turbulence. The augmented roll control is sensitive to configuration changes.
Low bandwidth robust controllers for flight
NASA Technical Reports Server (NTRS)
Biezad, Daniel J.; Chou, Hwei-Lan
1993-01-01
Through throttle manipulations, engine thrust can be used for emergency flight control for multi-engine aircraft. Previous study by NASA Dryden has shown the use of throttles for emergency flight control to be very difficult. In general, manual fly-by-throttle is extremely difficult - with landing almost impossible, but control augmentation makes runway landings feasible. Flight path control using throttles-only to achieve safe emergency landing for a large jet transport airplane, Boeing 720, was investigated using Quantitative Feedback Theory (QFT). Results were compared to an augmented control developed in a previous simulation study. The control augmentation corrected the unsatisfactory open-loop characteristics by increasing system bandwidth and damping, but increasing the control bandwidth substantially proved very difficult. The augmented pitch control is robust under no or moderate turbulence. The augmented roll control is sensitive to configuration changes.
Bretagne, Charles-Henri; Petitjean, Alain; Felix, Sophie; Bedgedjian, Isabelle; Algros, Marie-Paule; Delabrousse, Eric; Valmary-Degano, Séverine
2016-04-01
Peritoneal malignant mesothelioma is a rare and extremely aggressive tumor that is sometimes difficult to diagnose. We report two cases of metastatic malignant peritoneal mesothelioma. In one case, malignant metastatic cells were identified in cervical lymph nodes while in the other case, the cells were found in the liver. In both cases, metastases were identified before discovering the primary tumor. This led to the misdiagnosis of carcinoma of unknown origin. Nevertheless, the histological and immuno-histochemical patterns were typical of malignant mesothelioma. Regarding metastasis of unknown origin, a differentiation of epithelioid peritoneal malignant mesothelioma and adenocarcinoma proved to be difficult. Therefore, we discuss the diagnostic usefulness of immuno-histochemical mesothelioma markers. Copyright © 2015 Elsevier Masson SAS. All rights reserved.
Strifling, Kelly M B; Konop, Katherine A; Wang, Mei; Harris, Gerald F
2009-01-01
Walkers are prescribed with the notion that one type of walker will be better for a child than another. One underlying justification for this practice is the theory that one walker may produce less stress on the upper extremities as the patient uses the walker. Nevertheless, upper extremity joint loading is not typically analyzed during walker assisted gait in children with spastic diplegic cerebral palsy. It has been difficult to evaluate the theory of walker prescription based on upper extremity stresses because loading on the upper extremities however has not been quantified until recently. In this study, weight bearing on the glenohumeral joints was analyzed in five children with spastic diplegic cerebral palsy using both anterior and posterior walkers fitted with 6-axis handle transducers. Though walkers' effects on the upper extremities proved to be similar between walker types, the differences between the walkers may have some clinical significance in the long run. In general, posterior walker use created larger glenohumeral joint forces. Though these differences are not statistically significant, over time and with repetitive loading they may be clinically significant.
Uncertainty in determining extreme precipitation thresholds
NASA Astrophysics Data System (ADS)
Liu, Bingjun; Chen, Junfan; Chen, Xiaohong; Lian, Yanqing; Wu, Lili
2013-10-01
Extreme precipitation events are rare and occur mostly on a relatively small and local scale, which makes it difficult to set the thresholds for extreme precipitations in a large basin. Based on the long term daily precipitation data from 62 observation stations in the Pearl River Basin, this study has assessed the applicability of the non-parametric, parametric, and the detrended fluctuation analysis (DFA) methods in determining extreme precipitation threshold (EPT) and the certainty to EPTs from each method. Analyses from this study show the non-parametric absolute critical value method is easy to use, but unable to reflect the difference of spatial rainfall distribution. The non-parametric percentile method can account for the spatial distribution feature of precipitation, but the problem with this method is that the threshold value is sensitive to the size of rainfall data series and is subjected to the selection of a percentile thus make it difficult to determine reasonable threshold values for a large basin. The parametric method can provide the most apt description of extreme precipitations by fitting extreme precipitation distributions with probability distribution functions; however, selections of probability distribution functions, the goodness-of-fit tests, and the size of the rainfall data series can greatly affect the fitting accuracy. In contrast to the non-parametric and the parametric methods which are unable to provide information for EPTs with certainty, the DFA method although involving complicated computational processes has proven to be the most appropriate method that is able to provide a unique set of EPTs for a large basin with uneven spatio-temporal precipitation distribution. The consistency between the spatial distribution of DFA-based thresholds with the annual average precipitation, the coefficient of variation (CV), and the coefficient of skewness (CS) for the daily precipitation further proves that EPTs determined by the DFA method are more reasonable and applicable for the Pearl River Basin.
Modern steels at atomic and nanometre scales
Caballero, F. G.; Garcia-Mateo, C.; Miller, M. K.
2014-10-10
Processing bulk nanocrystalline materials for structural applications still poses a difficult challenge, particularly in achieving an industrially viable process. Recent work in ferritic steels has proved that it is possible to move from ultrafine to nanoscale by exploiting the bainite reaction without the use of severe deformation, rapid heat treatment or mechanical processing. This new generation of steels has been designed in which transformation at low temperature leads to a nanoscale structure consisting of extremely fine, 20–40 nm thick plates of bainitic ferrite and films of retained austenite. Finally, a description of the characteristics and significance of this remarkable microstructuremore » is provided here.« less
Infrared spectrum of an extremely cool white-dwarf star
Hodgkin; Oppenheimer; Hambly; Jameson; Smartt; Steele
2000-01-06
White dwarfs are the remnant cores of stars that initially had masses of less than 8 solar masses. They cool gradually over billions of years, and have been suggested to make up much of the 'dark matter' in the halo of the Milky Way. But extremely cool white dwarfs have proved difficult to detect, owing to both their faintness and their anticipated similarity in colour to other classes of dwarf stars. Recent improved models indicate that white dwarfs are much more blue than previously supposed, suggesting that the earlier searches may have been looking for the wrong kinds of objects. Here we report an infrared spectrum of an extremely cool white dwarf that is consistent with the new models. We determine the star's temperature to be 3,500 +/- 200 K, making it the coolest known white dwarf. The kinematics of this star indicate that it is in the halo of the Milky Way, and the density of such objects implied by the serendipitous discovery of this star is consistent with white dwarfs dominating the dark matter in the halo.
Raghava, Saripalli V; Srivastava, Bhartendu K; Ramshad, Kalluruttimmal; Antharjanam, Sudhadevi; Varghese, Babu; Muraleedharan, Kannoth M
2018-03-28
While supramolecular organisation is central to both crystallization and gelation, the latter is more complex considering its dynamic nature and multifactorial dependence. This makes the rational design of gelators an extremely difficult task. In this report, the assembly preference of a group of peptide-based sulfamides was modulated by making them part of an acid-amine two-component system to drive the tendency from crystallization to gelation. Here, the peptide core directed the assembly while the long-chain amines, introduced through salt-bridges, promoted layering and anisotropic development of primary aggregates. This proved to be very successful, leading to gelation of a number of solvents. Apart from this, it was possible to fine-tune their aggregation using an amphiphilic polymer like F-127 as an additive to get honey-comb-like 3D molecular architectures. These gels also proved to be excellent matrices for entrapping silver nanoparticles with superior emissive properties.
The Use of Bovine Collagen-glycosaminoglycan Matrix for Atypical Lower Extremity Ulcers.
Garwood, Caitlin S; Kim, Paul J; Matai, Vinay; Steinberg, John S; Evans, Karen K; Mitnick, Carol Deane B; Attinger, Christopher E
2016-09-01
The primary purpose of this study was to evaluate the use of bovine collagen-glycosaminoglycan matrix on atypical lower extremity ulcers. A retrospective chart review was performed on patients who underwent application of bovine collagen matrix to a lower extremity ulcer with an atypical etiology including autoimmune disease, sickle cell anemia, radiation therapy, connective tissue disease, vasculitis, or coagulopathy from January 2009 to October 2014. The following outcomes were evaluated: rate of ulcer healing and closure, number of ulcers that received a split-thickness skin graft, improvement in pain, and complications related to the ulcer. Thirty-eight patients with 71 lower extremity ulcers were analyzed. The most common ulcer etiolo- gies included rheumatoid arthritis, sickle cell anemia, and coagulopa- thy. After application of the bovine collagen matrix, 30 (42.3%) ulcers healed at a mean of 220.9 days. Of the 71 ulcers, 26 (36.6%) re- ceived a split-thickness skin graft after application of the matrix and 17 (65.4%) of those went on to complete healing. Ten patients had a local infection noted during follow-up, and 5 patients had dehiscence or dissociation of the matrix. Atypical lower extremity ulcers, such as those caused by autoimmune diseases and sickle cell anemia, proved difficult to heal. This case series shows that bovine collagen matrix can be a successful adjunctive therapy for the treatment of these challenging ulcers.
Rissanen, Ilona; Grimes, Jonathan M.; Pawlowski, Alice; Mäntynen, Sari; Harlos, Karl; Bamford, Jaana K.H.; Stuart, David I.
2013-01-01
Summary It has proved difficult to classify viruses unless they are closely related since their rapid evolution hinders detection of remote evolutionary relationships in their genetic sequences. However, structure varies more slowly than sequence, allowing deeper evolutionary relationships to be detected. Bacteriophage P23-77 is an example of a newly identified viral lineage, with members inhabiting extreme environments. We have solved multiple crystal structures of the major capsid proteins VP16 and VP17 of bacteriophage P23-77. They fit the 14 Å resolution cryo-electron microscopy reconstruction of the entire virus exquisitely well, allowing us to propose a model for both the capsid architecture and viral assembly, quite different from previously published models. The structures of the capsid proteins and their mode of association to form the viral capsid suggest that the P23-77-like and adeno-PRD1 lineages of viruses share an extremely ancient common ancestor. PMID:23623731
Measuring children's regulation of emotion-expressive behavior.
Bar-Haim, Yair; Bar-Av, Gali; Sadeh, Avi
2011-04-01
Emotion regulation has become a pivotal concept in developmental and clinical research. However, the measurement of regulatory processes has proved extremely difficult, particularly in the context of within-subject designs. Here, we describe a formal conceptualization and a new experimental procedure, the Balloons Game, to measure a regulatory component of emotion-expressive behavior. We present the internal consistency and stability of the indices derived from the Balloons Game in a sample of 121 kindergarten children. External validation against measures that have been associated with emotion regulation processes is also provided. The findings suggest that the Balloons Game provides a reliable tool for the study of regulation of emotion expression in young children. PsycINFO Database Record (c) 2011 APA, all rights reserved.
Proving allelopathy in crop-weed interactions
USDA-ARS?s Scientific Manuscript database
Allelopathy (plant/plant chemical warfare) is difficult to prove, especially when competition for resources is the dominant component of plant/plant interference (interference = allelopathy +competition). This paper describes experimental approaches for proving allelopathy and points out common pit...
GESA--a two-dimensional processing system using knowledge base techniques.
Rowlands, D G; Flook, A; Payne, P I; van Hoff, A; Niblett, T; McKee, S
1988-12-01
The successful analysis of two-dimensional (2-D) polyacrylamide electrophoresis gels demands considerable experience and understanding of the protein system under investigation as well as knowledge of the separation technique itself. The present work concerns the development of a computer system for analysing 2-D electrophoretic separations which incorporates concepts derived from artificial intelligence research such that non-experts can use the technique as a diagnostic or identification tool. Automatic analysis of 2-D gel separations has proved to be extremely difficult using statistical methods. Non-reproducibility of gel separations is also difficult to overcome using automatic systems. However, the human eye is extremely good at recognising patterns in images, and human intervention in semi-automatic computer systems can reduce the computational complexities of fully automatic systems. Moreover, the expertise and understanding of an "expert" is invaluable in reducing system complexity if it can be encapsulated satisfactorily in an expert system. The combination of user-intervention in the computer system together with the encapsulation of expert knowledge characterises the present system. The domain within which the system has been developed is that of wheat grain storage proteins (gliadins) which exhibit polymorphism to such an extent that cultivars can be uniquely identified by their gliadin patterns. The system can be adapted to other domains where a range of polymorpic protein sub-units exist. In its generalised form, the system can also be used for comparing more complex 2-D gel electrophoretic separations.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Fisher, C.G.
1993-03-01
An abrupt lithofacies change between calcareous shale and non-calcareous shale occurs in strata deposited in the mid-Cretaceous Greenhorn Seaway in the extreme southeastern corner of Montana, U.S.A. This strata, north of the Black Hills has previously been miss-correlated due to the extreme difficulty in locating unique continuous marker beds. Supplemental Graphic Correlation techniques of Lucy Edwards, which expand on those of Shaw, were employed in the difficult task of correlating across the Little Missouri River Valley. Precise correlation was necessary in order to interpret the cause of the lithofacies change. Edwards's use of non-unique event marker beds and the side-by-sidemore » graph method proved to be invaluable tools. Precise correlation across the facies change was accomplished using a combination of bentonite beds, calcarenite beds, ammonite species, foraminiferal and calcareous nannofossil assemblages. Supplemental Graphic Correlation techniques allowed the definition of twenty-five time slices and permitted the identification of an ocean front during each of these time slices.« less
Designer Drugs: A Synthetic Catastrophe.
Fratantonio, James; Andrade, Lawrence; Febo, Marcelo
Synthetic stimulants can cause hallucinations, aggressive behaviors, death and are sometimes legal. These substances are sold as plant food and bath salts that are "Not for Human Consumption", therefore skirting the 1986 Federal Analogue Act and giving a false pretense of safety. Studies have proved that these substances are toxic, have a high abuse potential, and are becoming extremely prevalent in the United States. This creates a dilemma for law enforcement agents, hospitals, and substance use disorder treatment centers. Urine Drug Testing is utilized as a clinical diagnostic tool in substance use disorder treatment centers, and the furious pace at which new synthetic stimulants are introduced to the black market are making the detection via urine increasingly difficult. This article will discuss the prevalence, pharmacology and difficulty developing laboratory assays to detect synthetic stimulants.
Extremes in Oxidizing Power, Acidity, and Basicity
2013-10-01
and extremely difficult to oxidize, with reversible redox potentials calculated up to 5 V above ferrocene /ferricenium. In liquid sulfur dioxide, the...ol, the undecafluorinated anion is oxidized reversibly at 2.43 V above ferrocene /ferricenium (calculated 2.40 V) but the radical is too unstable for...unusually weakly nucleophilic and extremely difficult to oxidize, with reversible redox potentials calculated up to 5 V above ferrocene /ferricenium. In
Oberklaid, F; Danks, D M; Jensen, F; Stace, L; Rosshandler, S
1979-04-01
An attempt was made to ascertain all the dwarfs in the State of Victoria. The incidence of achondroplasia proved to be approximately 1 in 26,000 live births in the period 1969 to 1975 when ascertainment was nearly complete. This indicates a mutation rate of 1.93 X 10(-5) per generation in this locus. Paternal age was shown to influence mutation. Ascertainment in earlier years of the study was low despite the very great effort made to find all cases. Patients with hypochondroplasia were particularly difficult to find. However, 25 cases were found for study. Overlap between hypochondroplasia and achondroplasia was found in all features except the facial appearance (which was the basis of definition). Achondroplasia was more severe in all regards, but some individuals with hypochondroplasia were very short and some had extreme degrees of spinal canal stenosis. The classical measurements used to describe the skull changes in acondroplasia failed to distinguish this condition from hypochondroplasia. More efficient indices were devised, but visual assessment of the size of the facial region compared to that of the cranial valult proved more reliable than any index. The clinical distinction based upon facial appearance remains the arbitrary basis of definition.
Picosecond amorphization of SiO2 stishovite under tension.
Misawa, Masaaki; Ryuo, Emina; Yoshida, Kimiko; Kalia, Rajiv K; Nakano, Aiichiro; Nishiyama, Norimasa; Shimojo, Fuyuki; Vashishta, Priya; Wakai, Fumihiro
2017-05-01
It is extremely difficult to realize two conflicting properties-high hardness and toughness-in one material. Nano-polycrystalline stishovite, recently synthesized from Earth-abundant silica glass, proved to be a super-hard, ultra-tough material, which could provide sustainable supply of high-performance ceramics. Our quantum molecular dynamics simulations show that stishovite amorphizes rapidly on the order of picosecond under tension in front of a crack tip. We find a displacive amorphization mechanism that only involves short-distance collective motions of atoms, thereby facilitating the rapid transformation. The two-step amorphization pathway involves an intermediate state akin to experimentally suggested "high-density glass polymorphs" before eventually transforming to normal glass. The rapid amorphization can catch up with, screen, and self-heal a fast-moving crack. This new concept of fast amorphization toughening likely operates in other pressure-synthesized hard solids.
DU Processing Efficiency and Reclamation: Plasma Arc Melting
DOE Office of Scientific and Technical Information (OSTI.GOV)
Imhoff, Seth D.; Aikin, Jr., Robert M.; Swenson, Hunter
The work described here corresponds to one piece of a larger effort to increase material usage efficiency during DU processing operations. In order to achieve this goal, multiple technologies and approaches are being tested. These technologies occupy a spectrum of technology readiness levels (TRLs). Plasma arc melting (PAM) is one of the technologies being investigated. PAM utilizes a high temperature plasma to melt materials. Depending on process conditions, there are potential opportunities for recycling and material reclamation. When last routinely operational, the LANL research PAM showed extremely promising results for recycling and reclamation of DU and DU alloys. The currentmore » TRL is lower due to machine idleness for nearly two decades, which has proved difficult to restart. This report describes the existing results, promising techniques, and the process of bringing this technology back to readiness at LANL.« less
Extreme Warming Challenges Sentinel Status of Kelp Forests as Indicators of Climate Change
NASA Astrophysics Data System (ADS)
Miller, R. J.; Reed, D.; Washburn, L.; Rassweiler, A.; Bell, T. W.; Harrer, S.
2016-12-01
The ecological effects of global warming are expected to be large, but are proving difficult and costly to measure. This has led to a growing interest in using sentinel species as early warning indicators of impending climate change effects on entire ecosystems, raising awareness of the importance of verifying that such conservation shortcuts have sound biological foundations. A recent large-scale warming event in the North Pacific Ocean of unprecedented magnitude and duration allowed us to evaluate the sentinel status of giant kelp, a coastal foundation species that thrives in cold, nutrient-rich waters and considered sensitive to warming. Here we show that giant kelp did not presage ecosystem effects of extreme warming off southern California despite its expected vulnerability. Fluctuations in the biomass of giant kelp, understory algae, invertebrates and fish remained within historical ranges despite 34 months of above average temperatures and below average nutrients. Sea stars and sea urchins were exceptions, plummeting due to disease outbreaks linked to the warming. Our results challenge the IPCC predictions about the vulnerability of kelp-dominated systems to extreme warming events and question their use as early indicators of climate change. The resilience of giant kelp to unprecedented warming not only questions our understanding of kelp ecology, but exposes the risk of relying on supposed sentinel species that are assumed to be very sensitive to climate change.
DOE R&D Accomplishments Database
Fermi, E.
1946-05-27
There is definitely a technical possibility that atomic power may gradually develop into one of the principal sources of useful power. If this expectation will prove correct, great advantages can be expected to come from the fact that the weight of the fuel is almost negligible. This feature may be particularly valuable for making power available to regions of difficult access and far from deposits of coal. It also may prove a great asset in mobile power units for example in a power plant for ship propulsion. On the negative side there are some technical limitations to be applicability of atomic power of which perhaps the most serious is the impossibility of constructing light power units; also there will be some peculiar difficulties in operating atomic plants, as for example the necessity of handling highly radioactive substances which will necessitate, at least for some considerable period, the use of specially skilled personnel for the operation. But the chief obstacle in the way of developing atomic power will be the difficulty of organizing a large scale industrial development in an internationally safe way. This presents actually problems much more difficult to solve than any of the technical developments that are necessary, It will require an unusual amount of statesmanship to balance properly the necessity of allaying the international suspicion that arises from withholding technical secrets against the obvious danger of dumping the details of the procedures for an extremely dangerous new method of warfare on a world that may not yet be prepared to renounce war. Furthermore, the proper balance should be found in the relatively short time that will elapse before the 'secrets' will naturally become open knowledge by rediscovery on part of the scientists and engineers of other countries.
Peñarrubia, Luis; Alcaraz, Carles; Vaate, Abraham Bij de; Sanz, Nuria; Pla, Carles; Vidal, Oriol; Viñas, Jordi
2016-12-14
The zebra mussel (Dreissena polymorpha Pallas, 1771) and the quagga mussel (D. rostriformis Deshayes, 1838) are successful invasive bivalves with substantial ecological and economic impacts in freshwater systems once they become established. Since their eradication is extremely difficult, their detection at an early stage is crucial to prevent spread. In this study, we optimized and validated a qPCR detection method based on the histone H2B gene to quantify combined infestation levels of zebra and quagga mussels in environmental DNA samples. Our results show specific dreissenid DNA present in filtered water samples for which microscopic diagnostic identification for larvae failed. Monitoring a large number of locations for invasive dreissenid species based on a highly specific environmental DNA qPCR assay may prove to be an essential tool for management and control plans focused on prevention of establishment of dreissenid mussels in new locations.
Peñarrubia, Luis; Alcaraz, Carles; Vaate, Abraham bij de; Sanz, Nuria; Pla, Carles; Vidal, Oriol; Viñas, Jordi
2016-01-01
The zebra mussel (Dreissena polymorpha Pallas, 1771) and the quagga mussel (D. rostriformis Deshayes, 1838) are successful invasive bivalves with substantial ecological and economic impacts in freshwater systems once they become established. Since their eradication is extremely difficult, their detection at an early stage is crucial to prevent spread. In this study, we optimized and validated a qPCR detection method based on the histone H2B gene to quantify combined infestation levels of zebra and quagga mussels in environmental DNA samples. Our results show specific dreissenid DNA present in filtered water samples for which microscopic diagnostic identification for larvae failed. Monitoring a large number of locations for invasive dreissenid species based on a highly specific environmental DNA qPCR assay may prove to be an essential tool for management and control plans focused on prevention of establishment of dreissenid mussels in new locations. PMID:27966602
NASA Astrophysics Data System (ADS)
Ji, Fang; Xu, Min; Wang, Baorui; Wang, Chao; Li, Xiaoyuan; Zhang, Yunfei; Zhou, Ming; Huang, Wen; Wei, Qilong; Tang, Guangping; He, Jianguo
2015-10-01
KDP is a common type of optics that is extremely difficult to polish by the conventional route. MRF is a local polishing technology based on material removal via shearing with minimal normal load and sub-surface damage. In contrast to traditional emendation on an abrasive, the MPEG soft coating is designed and prepared to modify the CIP surface to achieve a hardness matched with that of KDP because CIP inevitably takes part in the material removal during finishing. Morphology and infrared spectra are explored to prove the existence of homogeneous coating, and the improvement of MPEG for the polishing quality is validated by the analysis of roughness, turning grooves, and stress. The synthesized MPEG-coated CIP (MPEG-CIP) is chemically and physically compatible with KDP, which can be removed after cleaning. Our research exhibits the promising prospects of MPEG-CIP in KDP MRF.
[Provision System of Medical Narcotics].
Kushida, Kazuki; Toshima, Chiaki; Fujimaki, Yoko; Watanabe, Mutsuko; Hirohara, Masayoshi
2015-12-01
Patients with cancer are increasingly opting for home health care, resulting in a rapid increase in the number of prescriptions for narcotics aimed at pain control. As these narcotics are issued by pharmacies only upon presentation of valid prescriptions, the quantity stored in the pharmacies is of importance. Although many pharmaceutical outlets are certified for retail sale of narcotic drugs, the available stock is often extremely limited in variety and quantity. Affiliated stores of wholesale(or central wholesale)dealers do not always have the necessary certifications to provide medical narcotics. Invariably, the quantity stored by individual branches or sales offices is also limited. Hence, it may prove difficult to urgently secure the necessary and appropriate drugs according to prescription in certain areas of the community. This report discusses the problems faced by wholesalers and pharmacies during acquisition, storage, supply, and issue of prescription opioids from a stockpiling perspective.
Picosecond amorphization of SiO2 stishovite under tension
Misawa, Masaaki; Ryuo, Emina; Yoshida, Kimiko; Kalia, Rajiv K.; Nakano, Aiichiro; Nishiyama, Norimasa; Shimojo, Fuyuki; Vashishta, Priya; Wakai, Fumihiro
2017-01-01
It is extremely difficult to realize two conflicting properties—high hardness and toughness—in one material. Nano-polycrystalline stishovite, recently synthesized from Earth-abundant silica glass, proved to be a super-hard, ultra-tough material, which could provide sustainable supply of high-performance ceramics. Our quantum molecular dynamics simulations show that stishovite amorphizes rapidly on the order of picosecond under tension in front of a crack tip. We find a displacive amorphization mechanism that only involves short-distance collective motions of atoms, thereby facilitating the rapid transformation. The two-step amorphization pathway involves an intermediate state akin to experimentally suggested “high-density glass polymorphs” before eventually transforming to normal glass. The rapid amorphization can catch up with, screen, and self-heal a fast-moving crack. This new concept of fast amorphization toughening likely operates in other pressure-synthesized hard solids. PMID:28508056
Drilling Regolith: Why Is It So Difficult?
NASA Astrophysics Data System (ADS)
Schmitt, H. H.
2017-10-01
The Apollo rotary percussive drill system penetrated the lunar regolith with reasonable efficiency; however, extraction of the drill core stem proved to be very difficult on all three missions. Retractable drill stem flutes may solve this problem.
Oberklaid, F; Danks, D M; Jensen, F; Stace, L; Rosshandler, S
1979-01-01
An attempt was made to ascertain all the dwarfs in the State of Victoria. The incidence of achondroplasia proved to be approximately 1 in 26,000 live births in the period 1969 to 1975 when ascertainment was nearly complete. This indicates a mutation rate of 1.93 X 10(-5) per generation in this locus. Paternal age was shown to influence mutation. Ascertainment in earlier years of the study was low despite the very great effort made to find all cases. Patients with hypochondroplasia were particularly difficult to find. However, 25 cases were found for study. Overlap between hypochondroplasia and achondroplasia was found in all features except the facial appearance (which was the basis of definition). Achondroplasia was more severe in all regards, but some individuals with hypochondroplasia were very short and some had extreme degrees of spinal canal stenosis. The classical measurements used to describe the skull changes in acondroplasia failed to distinguish this condition from hypochondroplasia. More efficient indices were devised, but visual assessment of the size of the facial region compared to that of the cranial valult proved more reliable than any index. The clinical distinction based upon facial appearance remains the arbitrary basis of definition. Images PMID:458831
Phase Behavior of an Intact Monoclonal Antibody
Ahamed, Tangir; Esteban, Beatriz N. A.; Ottens, Marcel; van Dedem, Gijs W. K.; van der Wielen, Luuk A. M.; Bisschops, Marc A. T.; Lee, Albert; Pham, Christine; Thömmes, Jörg
2007-01-01
Understanding protein phase behavior is important for purification, storage, and stable formulation of protein drugs in the biopharmaceutical industry. Glycoproteins, such as monoclonal antibodies (MAbs) are the most abundant biopharmaceuticals and probably the most difficult to crystallize among water-soluble proteins. This study explores the possibility of correlating osmotic second virial coefficient (B22) with the phase behavior of an intact MAb, which has so far proved impossible to crystallize. The phase diagram of the MAb is presented as a function of the concentration of different classes of precipitants, i.e., NaCl, (NH4)2SO4, and polyethylene glycol. All these precipitants show a similar behavior of decreasing solubility with increasing precipitant concentration. B22 values were also measured as a function of the concentration of the different precipitants by self-interaction chromatography and correlated with the phase diagrams. Correlating phase diagrams with B22 data provides useful information not only for a fundamental understanding of the phase behavior of MAbs, but also for understanding the reason why certain proteins are extremely difficult to crystallize. The scaling of the phase diagram in B22 units also supports the existence of a universal phase diagram of a complex glycoprotein when it is recast in a protein interaction parameter. PMID:17449660
Nonmaximality of known extremal metrics on torus and Klein bottle
DOE Office of Scientific and Technical Information (OSTI.GOV)
Karpukhin, M A
2013-12-31
The El Soufi-Ilias theorem establishes a connection between minimal submanifolds of spheres and extremal metrics for eigenvalues of the Laplace-Beltrami operator. Recently, this connection was used to provide several explicit examples of extremal metrics. We investigate the properties of these metrics and prove that none of them is maximal. Bibliography: 24 titles.
Emerging communications technologies for outer-planet exploration
NASA Technical Reports Server (NTRS)
Stelzried, C.; Lesh, J.
2001-01-01
Communication over long free space distances is extremely difficult due to the inverse squared propagation losses associated with link distance. That makes communications particularly difficult from outer planet destinations.
Optimal bounds and extremal trajectories for time averages in dynamical systems
NASA Astrophysics Data System (ADS)
Tobasco, Ian; Goluskin, David; Doering, Charles
2017-11-01
For systems governed by differential equations it is natural to seek extremal solution trajectories, maximizing or minimizing the long-time average of a given quantity of interest. A priori bounds on optima can be proved by constructing auxiliary functions satisfying certain point-wise inequalities, the verification of which does not require solving the underlying equations. We prove that for any bounded autonomous ODE, the problems of finding extremal trajectories on the one hand and optimal auxiliary functions on the other are strongly dual in the sense of convex duality. As a result, auxiliary functions provide arbitrarily sharp bounds on optimal time averages. Furthermore, nearly optimal auxiliary functions provide volumes in phase space where maximal and nearly maximal trajectories must lie. For polynomial systems, such functions can be constructed by semidefinite programming. We illustrate these ideas using the Lorenz system, producing explicit volumes in phase space where extremal trajectories are guaranteed to reside. Supported by NSF Award DMS-1515161, Van Loo Postdoctoral Fellowships, and the John Simon Guggenheim Foundation.
Nebular Line Emission and Stellar Mass of Bright z 8 Galaxies "Super-Eights"
NASA Astrophysics Data System (ADS)
Holwerda, Benne; Bouwens, Rychard; Trenti, Michele; Oesch, Pascal; Labbe, Ivo; Smit, Renske; Roberts-Borsani, Guido; Bernard, Stephanie; Bridge, Joanna
2018-05-01
Searches for the Lyman-alpha emission from the very first galaxies ionizing the Universe have proved to be extremely difficult with limited success beyond z 7 (<3% detections). However, a search of all CANDELS yielded four bright z 8 sources with associated strong Lyman-alpha lines, despite the Universe expected to be 70% neutral at this time. The key to their selection is an extremely red IRAC color ([3.6]-[4.5]> 0.5, Roberts-Borsani+ 2016), indicative of very strong nebular line emission. Do such extreme line emitting galaxies produce most of the photons to reionize the Universe? We propose to expand the sample of bright z 8 galaxies with reliable IRAC colors with seven more Y-band dropouts found with HST and confirmed through HST/Spitzer. The Spitzer observations will test how many of bright z 8 galaxies are IRAC-red and measure both their stellar mass and [OIII]+Hbeta line strength. Together with Keck/VLT spectroscopy, they will address these questions: I) Do all luminous z 8 galaxies show such red IRAC colors ([OIII] emission / hard spectra)? II) Is luminosity or a red IRAC color the dominant predictor for Lyman-alpha emission? III) Or are these sources found along exceptionally transparent sightlines into the early Universe? With 11 bright z 8 sources along different lines-of-sight, all prime targets for JWST, we will aim to determine which of the considered factors (luminosity, color, sight-line) drives the high Lyman-alpha prevalence (100%) and insight into the sources reionizing the Universe.
A Fiducial Approach to Extremes and Multiple Comparisons
ERIC Educational Resources Information Center
Wandler, Damian V.
2010-01-01
Generalized fiducial inference is a powerful tool for many difficult problems. Based on an extension of R. A. Fisher's work, we used generalized fiducial inference for two extreme value problems and a multiple comparison procedure. The first extreme value problem is dealing with the generalized Pareto distribution. The generalized Pareto…
Coolant Design System for Liquid Propellant Aerospike Engines
NASA Astrophysics Data System (ADS)
McConnell, Miranda; Branam, Richard
2015-11-01
Liquid propellant rocket engines burn at incredibly high temperatures making it difficult to design an effective coolant system. These particular engines prove to be extremely useful by powering the rocket with a variable thrust that is ideal for space travel. When combined with aerospike engine nozzles, which provide maximum thrust efficiency, this class of rockets offers a promising future for rocketry. In order to troubleshoot the problems that high combustion chamber temperatures pose, this research took a computational approach to heat analysis. Chambers milled into the combustion chamber walls, lined by a copper cover, were tested for their efficiency in cooling the hot copper wall. Various aspect ratios and coolants were explored for the maximum wall temperature by developing our own MATLAB code. The code uses a nodal temperature analysis with conduction and convection equations and assumes no internal heat generation. This heat transfer research will show oxygen is a better coolant than water, and higher aspect ratios are less efficient at cooling. This project funded by NSF REU Grant 1358991.
Radiometric dating of the Siloam Tunnel, Jerusalem.
Frumkin, Amos; Shimron, Aryeh; Rosenbaum, Jeff
2003-09-11
The historical credibility of texts from the Bible is often debated when compared with Iron Age archaeological finds (refs. 1, 2 and references therein). Modern scientific methods may, in principle, be used to independently date structures that seem to be mentioned in the biblical text, to evaluate its historical authenticity. In reality, however, this approach is extremely difficult because of poor archaeological preservation, uncertainty in identification, scarcity of datable materials, and restricted scientific access into well-identified worship sites. Because of these problems, no well-identified Biblical structure has been radiometrically dated until now. Here we report radiocarbon and U-Th dating of the Siloam Tunnel, proving its Iron Age II date; we conclude that the Biblical text presents an accurate historic record of the Siloam Tunnel's construction. Being one of the longest ancient water tunnels lacking intermediate shafts, dating the Siloam Tunnel is a key to determining where and when this technological breakthrough took place. Siloam Tunnel dating also refutes a claim that the tunnel was constructed in the second century bc.
Extremophiles in Household Water Heaters
NASA Astrophysics Data System (ADS)
Wilpiszeski, R.; House, C. H.
2016-12-01
A significant fraction of Earth's microbial diversity comes from species living in extreme environments, but natural extreme environments can be difficult to access. Manmade systems like household water heaters serve as an effective proxy for thermophilic environments that are otherwise difficult to sample directly. As such, we are investigating the biogeography, taxonomic distribution, and evolution of thermophiles growing in domestic water heaters. Citizen scientists collected hot tap water culture- and filter- samples from 101 homes across the United States. We recovered a single species of thermophilic heterotroph from culture samples inoculated from water heaters across the United States, Thermus scotoductus. Whole-genome sequencing was conducted to better understand the distribution and evolution of this single species. We have also sequenced hyper-variable regions of the 16S rRNA gene from whole-community filter samples to identify the broad diversity and distribution of microbial cells captured from each water heater. These results shed light on the processes that shape thermophilic populations and genomes at a spatial resolution that is difficult to access in naturally occurring extreme ecosystems.
Tribal Colleges: The Original Extreme Makeover Experts
ERIC Educational Resources Information Center
Powless, Donna
2015-01-01
In this article, the author states "our experience with education is a prime example in proving we are experts at problem-solving and are the originators of the extreme makeover." Educational institutions were introduced to the Native people in an outrageous manner--often as a mask for assimilating American Indians, routinely resulting…
Mattern, Thomas; Meyer, Stefan; Ellenberg, Ursula; Houston, David M; Darby, John T; Young, Melanie; van Heezik, Yolanda; Seddon, Philip J
2017-01-01
Climate change is a global issue with effects that are difficult to manage at a regional scale. Yet more often than not climate factors are just some of multiple stressors affecting species on a population level. Non-climatic factors-especially those of anthropogenic origins-may play equally important roles with regard to impacts on species and are often more feasible to address. Here we assess the influence of climate change on population trends of the endangered Yellow-eyed penguin ( Megadyptes antipodes ) over the last 30 years, using a Bayesian model. Sea surface temperature (SST) proved to be the dominating factor influencing survival of both adult birds and fledglings. Increasing SST since the mid-1990s was accompanied by a reduction in survival rates and population decline. The population model showed that 33% of the variation in population numbers could be explained by SST alone, significantly increasing pressure on the penguin population. Consequently, the population becomes less resilient to non-climate related impacts, such as fisheries interactions, habitat degradation and human disturbance. However, the extent of the contribution of these factors to declining population trends is extremely difficult to assess principally due to the absence of quantifiable data, creating a discussion bias towards climate variables, and effectively distracting from non-climate factors that can be managed on a regional scale to ensure the viability of the population.
Zou, Shanmei; Fei, Cong; Wang, Chun; Gao, Zhan; Bao, Yachao; He, Meilin; Wang, Changhai
2016-01-01
Microalgae identification is extremely difficult. The efficiency of DNA barcoding in microalgae identification involves ideal gene markers and approaches employed, which however, is still under the way. Although Scenedesmus has obtained much research in producing lipids its identification is difficult. Here we present a comprehensive coalescent, distance and character-based DNA barcoding for 118 Scenedesmus strains based on rbcL, tufA, ITS and 16S. The four genes, and their combined data rbcL + tufA + ITS + 16S, rbcL + tufA and ITS + 16S were analyzed by all of GMYC, P ID, PTP, ABGD, and character-based barcoding respectively. It was apparent that the three combined gene data showed a higher proportion of resolution success than the single gene. In comparison, the GMYC and PTP analysis produced more taxonomic lineages. The ABGD generated various resolution in discrimination among the single and combined data. The character-based barcoding was proved to be the most effective approach for species discrimination in both single and combined data which produced consistent species identification. All the integrated results recovered 11 species, five out of which were revealed as potential cryptic species. We suggest that the character-based DNA barcoding together with other approaches based on multiple genes and their combined data could be more effective in microalgae diversity revelation. PMID:27827440
Zou, Shanmei; Fei, Cong; Wang, Chun; Gao, Zhan; Bao, Yachao; He, Meilin; Wang, Changhai
2016-11-09
Microalgae identification is extremely difficult. The efficiency of DNA barcoding in microalgae identification involves ideal gene markers and approaches employed, which however, is still under the way. Although Scenedesmus has obtained much research in producing lipids its identification is difficult. Here we present a comprehensive coalescent, distance and character-based DNA barcoding for 118 Scenedesmus strains based on rbcL, tufA, ITS and 16S. The four genes, and their combined data rbcL + tufA + ITS + 16S, rbcL + tufA and ITS + 16S were analyzed by all of GMYC, P ID, PTP, ABGD, and character-based barcoding respectively. It was apparent that the three combined gene data showed a higher proportion of resolution success than the single gene. In comparison, the GMYC and PTP analysis produced more taxonomic lineages. The ABGD generated various resolution in discrimination among the single and combined data. The character-based barcoding was proved to be the most effective approach for species discrimination in both single and combined data which produced consistent species identification. All the integrated results recovered 11 species, five out of which were revealed as potential cryptic species. We suggest that the character-based DNA barcoding together with other approaches based on multiple genes and their combined data could be more effective in microalgae diversity revelation.
[Constructing a database that can input record of use and product-specific information].
Kawai, Satoru; Satoh, Kenichi; Yamamoto, Hideo
2012-01-01
In Japan, patients were infected by viral hepatitis C generally by administering a specific fibrinogen injection. However, it has been difficult to identify patients who were infected as result of the injections due to the lack of medical records. It is still not a common practice by a number of medical facilities to maintain detailed information because manual record keeping is extremely time consuming and subject to human error. Due to these reasons, the regulator required Medical device manufacturers and pharmaceutical companies to attach a bar code called "GS1-128" effective March 28, 2008. Based on this new process, we have come up with the idea of constructing a new database whose records can be entered by bar code scanning to ensure data integrity. Upon examining the efficacy of this new data collection process from the perspective of time efficiency and of course data accuracy, "GS1-128" proved that it significantly reduces time and record keeping mistakes. Patients not only became easily identifiable by a lot number and a serial number when immediate care was required, but "GS1-128" enhanced the ability to pinpoint manufacturing errors in the event any trouble or side effects are reported. This data can be shared with and utilized by the entire medical industry and will help perfect the products and enhance record keeping. I believe this new process is extremely important.
Chaos, Fractals, and the Pedagogical Challenge of Jackson Pollock's "All-Over" Paintings
ERIC Educational Resources Information Center
Halsall, Francis
2008-01-01
The "all-over" abstract canvases that Jackson Pollock produced between 1943 and 1951 present a pedagogical challenge in how to account for their apparently chaotic structure. One reason that they are difficult to teach about is that they have proved notoriously difficult for art historians to come to terms with. This is undoubtedly a consequence…
The impact of Pulpwood Rail Freight Costs on the Minnesota-Wisconsin Pulpwood Market
David C. Lothner
1976-01-01
Transportation costs affect the marketing and utilization of pulpwood. Their impact on the procurement and utilization of pulpwood often prove difficult to measure because deriving an average annual measure of the transportation cost is difficult. This note, by means of a simple index method for measuring regional interstate pulpwood rail freight costs, illustrates...
ERIC Educational Resources Information Center
Batey, Mark
2012-01-01
The scientific study of creativity has proven a difficult undertaking. Researchers have employed a diversity of definitions and measurement methods. As a result, creativity research is underrepresented in the literature and the findings of different studies often prove difficult to draw into a coherent body of understanding. A heuristic framework…
NASA Astrophysics Data System (ADS)
Laurie, J.; Bouchet, F.
2012-04-01
Many turbulent flows undergo sporadic random transitions, after long periods of apparent statistical stationarity. For instance, paths of the Kuroshio [1], the Earth's magnetic field reversal, atmospheric flows [2], MHD experiments [3], 2D turbulence experiments [4,5], 3D flows [6] show this kind of behavior. The understanding of this phenomena is extremely difficult due to the complexity, the large number of degrees of freedom, and the non-equilibrium nature of these turbulent flows. It is however a key issue for many geophysical problems. A straightforward study of these transitions, through a direct numerical simulation of the governing equations, is nearly always impracticable. This is mainly a complexity problem, due to the large number of degrees of freedom involved for genuine turbulent flows, and the extremely long time between two transitions. In this talk, we consider two-dimensional and geostrophic turbulent models, with stochastic forces. We consider regimes where two or more attractors coexist. As an alternative to direct numerical simulation, we propose a non-equilibrium statistical mechanics approach to the computation of this phenomenon. Our strategy is based on large deviation theory [7], derived from a path integral representation of the stochastic process. Among the trajectories connecting two non-equilibrium attractors, we determine the most probable one. Moreover, we also determine the transition rates, and in which cases this most probable trajectory is a typical one. Interestingly, we prove that in the class of models we consider, a mechanism exists for diffusion over sets of connected attractors. For the type of stochastic forces that allows this diffusion, the transition between attractors is not a rare event. It is then very difficult to characterize the flow as bistable. However for another class of stochastic forces, this diffusion mechanism is prevented, and genuine bistability or multi-stability is observed. We discuss how these results are probably connected to the long debated existence of multi-stability in the atmosphere and oceans.
1996-01-01
irrevocable steps toward war. This balancing act proved impossible to perform even for the culturally similar and aristocratically governed states...of 19th- century Europe. It is likely to prove infinitely more difficult when the system is global; the participants differ culturally ; and the...symmetries among the challenges along Eu- rope’s eastern and southern arcs are obvious. History, geography, and culture make enormous differences. While the
The Highly-Automated Airplane: Its Impact on Aviation Safety and an Analysis of Training Philosophy.
1997-06-01
equipment. This means more than just knowing how to program the device and being familiar with the functions of varying modes (Patrick, 1996:18). 33...the function that I wanted to use or modify in a flight plan." "Initially it is extremely difficult to figure out exactly how to program or pull up...commented: "Getting used to the EFIS display was the hardest. Initially it is extremely difficult to figure out exactly how to program or pull up the
Holographic entanglement entropy conjecture for general spacetimes
NASA Astrophysics Data System (ADS)
Sanches, Fabio; Weinberg, Sean J.
2016-10-01
We present a natural generalization of holographic entanglement entropy proposals beyond the scope of AdS /CFT by anchoring extremal surfaces to holographic screens. Holographic screens are a natural extension of the AdS boundary to arbitrary spacetimes and are preferred codimension-1 surfaces from the viewpoint of the covariant entropy bound. A broad class of screens have a unique preferred foliation into codimension-2 surfaces called leaves. Our proposal is to find the areas of extremal surfaces anchored to the boundaries of regions in leaves. We show that the properties of holographic screens are sufficient to prove, under generic conditions, that extremal surfaces anchored in this way always lie within a causal region associated with a given leaf. Within this causal region, a maximin construction similar to that of Wall proves that our proposed quantity satisfies standard properties of entanglement entropy like strong subadditivity. We conjecture that our prescription computes entanglement entropies in quantum states that holographically define arbitrary spacetimes, including those in a cosmological setting with no obvious boundary on which to anchor extremal surfaces.
Kunda, Z; Oleson, K C
1997-05-01
The authors examined how the extent to which counterstereotypic individuals deviate from perceivers' stereotypes affects their impact on these stereotypes and found that extremely deviant group members provoke less stereotype assimilation than do moderately deviant ones. Extremely deviant examples can even provoke boomerang effects, that is, enhance the very stereotype that they violate. When participants whose prior stereotype were moderate or extreme were exposed to moderately or extremely deviant examples, the deviant examples' impact on stereotypes depended both on their extremity and on the extremity of perceivers' prior stereotypes. Boomerang effects were obtained only for extreme-stereotype participants exposed to extremely deviant examples and were mediated by perceptions of the typicality of the deviant examples. Open-ended explanations revealed that the atypicality of extremely deviant examples was used as grounds for dismissing them.
Isolation of carbohydrate-metabolizing, extremely halophilic bacteria.
NASA Technical Reports Server (NTRS)
Tomlinson, G. A.; Hochstein, L. I.
1972-01-01
Four previously unrecognized strains of extremely halophilic bacteria that utilize carbohydrates have been isolated. Gas production proved an unreliable index of carbohydrate metabolism; therefore, carbohydrate utilization was measured by determining acid formation and sugar disappearance during growth. By these procedures, carbohydrate utilization was readily detected. The results suggest that carbohydrate dissimilation by extremely halophilic bacteria may be more common than previously thought and that the apparent rarity of carbohydrate-metabolizing halophiles may be an artifact of the isolation procedures used.
Guha, Nishan; Dashwood, Alexander; Thomas, Nicholas J; Skingle, Alexander J; Sönksen, Peter H; Holt, Richard I G
2009-09-01
It is widely believed that growth hormone (GH) is abused by athletes for its anabolic and lipolytic effects. Many of the physiological effects of GH are mediated by the production of insulin-like growth factor-I (IGF-I). Both GH and IGF-I appear on the World Anti-Doping Agency list of prohibited substances. Little is known, however, about the prevalence of abuse with exogenous IGF-I. IGF-I has effects on carbohydrate, lipid and protein metabolism and some of these actions could prove beneficial to competitive athletes. No studies have demonstrated a positive effect of IGF-I on physical performance in healthy individuals but this has not yet been studied in appropriately designed trials. Two pharmaceutical preparations of IGF-I have recently become available for the treatment of growth disorders in children. This availability is likely to increase the prevalence of IGF-I abuse. Combining IGF-I with its binding protein IGFBP-3 in one preparation has the potential to reduce the side-effect profile but the adverse effects of long term IGF-I abuse are currently unknown. Detection of abuse with IGF-I is a major challenge for anti-doping authorities. It is extremely difficult to distinguish the exogenous recombinant form of the hormone from endogenously-produced IGF-I. One approach currently being investigated is based on measuring markers of GH and IGF-I action. This has already proved successful in the fight against GH abuse and, it is hoped, will subsequently lead to a similar test for detection of IGF-I abuse.
Ekstrand, Elisabeth; Rylander, Lars; Lexell, Jan; Brogårdh, Christina
2016-11-02
Despite that disability of the upper extremity is common after stroke, there is limited knowledge how it influences self-perceived ability to perform daily hand activities. The aim of this study was to describe which daily hand activities that persons with mild to moderate impairments of the upper extremity after stroke perceive difficult to perform and to evaluate how several potential factors are associated with the self-perceived performance. Seventy-five persons (72 % male) with mild to moderate impairments of the upper extremity after stroke (4 to 116 months) participated. Self-perceived ability to perform daily hand activities was rated with the ABILHAND Questionnaire. The perceived ability to perform daily hand activities and the potentially associated factors (age, gender, social and vocational situation, affected hand, upper extremity pain, spasticity, grip strength, somatosensation of the hand, manual dexterity, perceived participation and life satisfaction) were evaluated by linear regression models. The activities that were perceived difficult or impossible for a majority of the participants were bimanual tasks that required fine manual dexterity of the more affected hand. The factor that had the strongest association with perceived ability to perform daily hand activities was dexterity (p < 0.001), which together with perceived participation (p = 0.002) explained 48 % of the variance in the final multivariate model. Persons with mild to moderate impairments of the upper extremity after stroke perceive that bimanual activities requiring fine manual dexterity are the most difficult to perform. Dexterity and perceived participation are factors specifically important to consider in the rehabilitation of the upper extremity after stroke in order to improve the ability to use the hands in daily life.
Reliability of M256 Chemical Agent Detector Kit at Extreme Environmental Temperatures
1988-02-01
therefore not discussed. 4 In a study conducted at Yuma Proving Ground (Ref. 3), 1256 Kits were sub- jected to a iO-day field-cdrry test; the samplers were... Proving Ground , Dugway, Utah, June 197-. 5. Zylstra, ).R. Letter Report of Cold Regions Piiase of DT 11 (Environmental ) and Agent Ci"a- Tf6- -Mib5...Dugway Proving Ground , ATTN: STEDP-SD-TA, Dugway, UT 84022-5000. ECBC memo dtd 14 Oct 2014 AD _ _ _ _ _ _ RDTA PROJECT NO. I-M-466710DO49 TECOM PROJT NO. 8
YouTube Video as Health Literacy Tool: A Test of Body Image Campaign Effectiveness.
Meng, Juan; Bissell, Kim L; Pan, Po-Lin
2015-01-01
This study examined the effectiveness of four media campaigns about disordered eating behaviors. It investigated possible factors that affected females' perceived effectiveness of four campaign videos. Results indicated that health campaign about a celebrity's struggle with extreme thinness proved to be the least effective of four campaign videos, whereas the video presenting solid facts about the dangers of extreme dieting was perceived as the most effective campaign. Self-discrepancy was not a significant predictor to females' perceived effectiveness of campaign videos. Similarly, the frequency of Internet usage was proved as a weak predictor of their perceived effectiveness. These findings and the possible rationale for the lack of support with regard to the correlates of campaign effectiveness were also discussed.
Optimal bounds and extremal trajectories for time averages in nonlinear dynamical systems
NASA Astrophysics Data System (ADS)
Tobasco, Ian; Goluskin, David; Doering, Charles R.
2018-02-01
For any quantity of interest in a system governed by ordinary differential equations, it is natural to seek the largest (or smallest) long-time average among solution trajectories, as well as the extremal trajectories themselves. Upper bounds on time averages can be proved a priori using auxiliary functions, the optimal choice of which is a convex optimization problem. We prove that the problems of finding maximal trajectories and minimal auxiliary functions are strongly dual. Thus, auxiliary functions provide arbitrarily sharp upper bounds on time averages. Moreover, any nearly minimal auxiliary function provides phase space volumes in which all nearly maximal trajectories are guaranteed to lie. For polynomial equations, auxiliary functions can be constructed by semidefinite programming, which we illustrate using the Lorenz system.
Two conditions for equivalence of 0-norm solution and 1-norm solution in sparse representation.
Li, Yuanqing; Amari, Shun-Ichi
2010-07-01
In sparse representation, two important sparse solutions, the 0-norm and 1-norm solutions, have been receiving much of attention. The 0-norm solution is the sparsest, however it is not easy to obtain. Although the 1-norm solution may not be the sparsest, it can be easily obtained by the linear programming method. In many cases, the 0-norm solution can be obtained through finding the 1-norm solution. Many discussions exist on the equivalence of the two sparse solutions. This paper analyzes two conditions for the equivalence of the two sparse solutions. The first condition is necessary and sufficient, however, difficult to verify. Although the second is necessary but is not sufficient, it is easy to verify. In this paper, we analyze the second condition within the stochastic framework and propose a variant. We then prove that the equivalence of the two sparse solutions holds with high probability under the variant of the second condition. Furthermore, in the limit case where the 0-norm solution is extremely sparse, the second condition is also a sufficient condition with probability 1.
Characteristics and safety assessment of intractable proteins in genetically modified crops.
Bushey, Dean F; Bannon, Gary A; Delaney, Bryan F; Graser, Gerson; Hefford, Mary; Jiang, Xiaoxu; Lee, Thomas C; Madduri, Krishna M; Pariza, Michael; Privalle, Laura S; Ranjan, Rakesh; Saab-Rincon, Gloria; Schafer, Barry W; Thelen, Jay J; Zhang, John X Q; Harper, Marc S
2014-07-01
Genetically modified (GM) crops may contain newly expressed proteins that are described as "intractable". Safety assessment of these proteins may require some adaptations to the current assessment procedures. Intractable proteins are defined here as those proteins with properties that make it extremely difficult or impossible with current methods to express in heterologous systems; isolate, purify, or concentrate; quantify (due to low levels); demonstrate biological activity; or prove equivalency with plant proteins. Five classes of intractable proteins are discussed here: (1) membrane proteins, (2) signaling proteins, (3) transcription factors, (4) N-glycosylated proteins, and (5) resistance proteins (R-proteins, plant pathogen recognition proteins that activate innate immune responses). While the basic tiered weight-of-evidence approach for assessing the safety of GM crops proposed by the International Life Sciences Institute (ILSI) in 2008 is applicable to intractable proteins, new or modified methods may be required. For example, the first two steps in Tier I (hazard identification) analysis, gathering of applicable history of safe use (HOSU) information and bioinformatics analysis, do not require protein isolation. The extremely low level of expression of most intractable proteins should be taken into account while assessing safety of the intractable protein in GM crops. If Tier II (hazard characterization) analyses requiring animal feeding are judged to be necessary, alternatives to feeding high doses of pure protein may be needed. These alternatives are discussed here. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Wang, Jiali; Han, Yuefeng; Stein, Michael L.
2016-02-10
The Weather Research and Forecast (WRF) model downscaling skill in extreme maximum daily temperature is evaluated by using the generalized extreme value (GEV) distribution. While the GEV distribution has been used extensively in climatology and meteorology for estimating probabilities of extreme events, accurately estimating GEV parameters based on data from a single pixel can be difficult, even with fairly long data records. This work proposes a simple method assuming that the shape parameter, the most difficult of the three parameters to estimate, does not vary over a relatively large region. This approach is applied to evaluate 31-year WRF-downscaled extreme maximummore » temperature through comparison with North American Regional Reanalysis (NARR) data. Uncertainty in GEV parameter estimates and the statistical significance in the differences of estimates between WRF and NARR are accounted for by conducting bootstrap resampling. Despite certain biases over parts of the United States, overall, WRF shows good agreement with NARR in the spatial pattern and magnitudes of GEV parameter estimates. Both WRF and NARR show a significant increase in extreme maximum temperature over the southern Great Plains and southeastern United States in January and over the western United States in July. The GEV model shows clear benefits from the regionally constant shape parameter assumption, for example, leading to estimates of the location and scale parameters of the model that show coherent spatial patterns.« less
Nickel-hydrogen battery state of charge during low rate trickle charging
NASA Technical Reports Server (NTRS)
Lurie, C.; Foroozan, S.; Brewer, J.; Jackson, L.
1996-01-01
The NASA AXAF-I program requires high battery state of charge at launch. Traditional approaches to providing high state of charge, during prelaunch operations, require significant battery cooling. The use of active cooling, in the AXAF-I prelaunch environment, was considered and proved to be difficult to implement and very expensive. Accordingly alternate approaches were considered. An approach utilizing adiabatic charging and low rate trickle charge, was investigated and proved successful.
Neurosurgical rare disease: solitary plasmacytoma of the skull - case report and literature review.
Rizea, Radu Eugen; Popescu, Mihai; Gheorghiţă, Karina Lidia; Popescu, George; Neamţu, Marius Cristian; Busuioc, Cristina Jana; Ciurea, Alexandru Vlad
2018-01-01
Solitary extranevraxial plasmacytoma (SEP), as a clinical entity without signs of systemic myelomatosis, is extremely rare; it is difficult to find literature on the issue of patient management and proper course of action in the presence of associated pathology. The authors present a rare case of plasmacytoma of the skull vault associated with severe cardiac pathology, which made surgery extremely difficult and possible only through temporization of the interventions, as presented. We discuss our findings and opportunities for treatment in this case, which seemed unapproachable at presentation, in connection with the associated cardiac pathology. The case was followed-up for eight years with no recurrences.
7 CFR 1434.15 - Personal liability..
Code of Federal Regulations, 2014 CFR
2014-01-01
...) The producer and CCC agree that it will be difficult, if not impossible, to prove the amount of... removed by CCC, containing mercurial compounds or other substances poisonous to humans, animals, or food...
7 CFR 1434.15 - Personal liability..
Code of Federal Regulations, 2013 CFR
2013-01-01
...) The producer and CCC agree that it will be difficult, if not impossible, to prove the amount of... removed by CCC, containing mercurial compounds or other substances poisonous to humans, animals, or food...
7 CFR 1434.15 - Personal liability..
Code of Federal Regulations, 2012 CFR
2012-01-01
...) The producer and CCC agree that it will be difficult, if not impossible, to prove the amount of... removed by CCC, containing mercurial compounds or other substances poisonous to humans, animals, or food...
NASA Astrophysics Data System (ADS)
Jamaludin, A. S.; Hosokawa, A.; Furumoto, T.; Koyano, T.; Hashimoto, Y.
2018-03-01
Cutting process of difficult-to-cut material such as stainless steel, generates immensely excessive heat, which is one of the major causes related to shortening tool life and lower quality of surface finish. It is proven that application of cutting fluid during the cutting process of difficult-to-cut material is able to improve the cutting performance, but excessive application of cutting fluid leads to another problem such as increasing processing cost and environmental hazardous pollution of workplace. In the study, Extreme Cold Mist system is designed and tested along with various Minimum Quantity Lubrication (MQL) systems on turning process of stainless steel AISI 316. In the study, it is obtained that, Extreme Cold Mist system is able to reduce cutting force up to 60N and improve the surface roughness of the machined surface significantly.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Wilbanks, Thomas J.; Fernandez, Steven J.; Allen, Melissa R.
The President s Climate Change Action Plan calls for the development of better science, data, and tools for climate preparedness. Many of the current questions about preparedness for extreme weather events in coming decades are, however, difficult to answer with assets that have been developed by climate science to answer longer-term questions about climate change. Capacities for projecting exposures to climate-related extreme events, along with their implications for interconnected infrastructures, are now emerging.
Wilbanks, Thomas J.; Fernandez, Steven J.; Allen, Melissa R.
2015-06-23
The President s Climate Change Action Plan calls for the development of better science, data, and tools for climate preparedness. Many of the current questions about preparedness for extreme weather events in coming decades are, however, difficult to answer with assets that have been developed by climate science to answer longer-term questions about climate change. Capacities for projecting exposures to climate-related extreme events, along with their implications for interconnected infrastructures, are now emerging.
Courting, Marriage and Death in Colombia: An Interview.
ERIC Educational Resources Information Center
Richardson, Constance
There are a variety of methods to impart the cultural setting of a foreign language. The teacher can use, among other things, cultural assimilators, films, mini-dramas, culture capsules, background lectures, and native-speaking class visitors. This last technique can be extremely effective but difficult to arrange and difficult to control once it…
Learned Helplessness: The Effect of Failure on Test-Taking
ERIC Educational Resources Information Center
Firmin, Michael; Hwang, Chi-En; Copella, Margaret; Clark, Sarah
2004-01-01
This study examined learned helplessness and its effect on test taking. Students were given one of two tests; the first began with extremely difficult questions and the other started with easy questions. The researchers hypothesized that those who took the test beginning with difficult questions would become easily frustrated and possibly doubt…
Bound on the Slope of Steady Water Waves with Favorable Vorticity
NASA Astrophysics Data System (ADS)
Strauss, Walter A.; Wheeler, Miles H.
2016-12-01
We consider the angle {θ} of inclination (with respect to the horizontal) of the profile of a steady two dimensional inviscid symmetric periodic or solitary water wave subject to gravity. Although {θ} may surpass 30° for some irrotational waves close to the extreme wave, Amick (Arch Ration Mech Anal 99(2):91-114, 1987) proved that for any irrotational wave the angle must be less than 31.15°. Is the situation similar for periodic or solitary waves that are not irrotational? The extreme Gerstner wave has infinite depth, adverse vorticity and vertical cusps ( θ = 90°). Moreover, numerical calculations show that even waves of finite depth can overturn if the vorticity is adverse. In this paper, on the other hand, we prove an upper bound of 45° on {θ} for a large class of waves with favorable vorticity and finite depth. In particular, the vorticity can be any constant with the favorable sign. We also prove a series of general inequalities on the pressure within the fluid, including the fact that any overturning wave must have a pressure sink.
Psychology: Climate change hits home
NASA Astrophysics Data System (ADS)
Weber, Elke U.
2011-04-01
Engaging the public with climate change has proved difficult, in part because they see the problem as remote. New evidence suggests that direct experience of one anticipated impact -- flooding -- increases people's concern and willingness to save energy.
Human immunodeficiency virus infection and pneumothorax
Terzi, Eirini; Zarogoulidis, Konstantinos; Kougioumtzi, Ioanna; Dryllis, Georgios; Kioumis, Ioannis; Pitsiou, Georgia; Machairiotis, Nikolaos; Katsikogiannis, Nikolaos; Tsiouda, Theodora; Madesis, Athanasios; Karaiskos, Theodoros
2014-01-01
Pneumothorax is a serious and relatively frequent complication of human immunodeficiency virus (HIV) infection that may associate with increased morbidity and mortality and may prove difficult to manage, especially in patients with acquired immunodeficiency syndrome (AIDS). PMID:25337392
Estimating cull in northern hardwoods
W.M. Zillgitt; S.R. Gevorkiantz
1946-01-01
Cull in northern hardwood stands is often very heavy and is difficult to estimate. To help clarify this situation and aid the average cruiser to become more accurate in his estimates, the study reported here should prove very helpful.
2010-01-01
infection, or avascular necrosis is extremely difficult. Tibiocalcaneal fusion typically leaves a patient with a leg length discrepancy unless large bone...fractures. J Orthop Trauma 2004;18(5):265–70. 37. Dennison MG, Pool RD, Simonis RB, et al. Tibiocalcaneal fusion for avascular necrosis of the talus
A Localized Ensemble Kalman Smoother
NASA Technical Reports Server (NTRS)
Butala, Mark D.
2012-01-01
Numerous geophysical inverse problems prove difficult because the available measurements are indirectly related to the underlying unknown dynamic state and the physics governing the system may involve imperfect models or unobserved parameters. Data assimilation addresses these difficulties by combining the measurements and physical knowledge. The main challenge in such problems usually involves their high dimensionality and the standard statistical methods prove computationally intractable. This paper develops and addresses the theoretical convergence of a new high-dimensional Monte-Carlo approach called the localized ensemble Kalman smoother.
Current thinking about acute compartment syndrome of the lower extremity
Shadgan, Babak; Menon, Matthew; Sanders, David; Berry, Gregg; Martin, Claude; Duffy, Paul; Stephen, David; O’Brien, Peter J.
2010-01-01
Acute compartment syndrome of the lower extremity is a clinical condition that, although uncommon, is seen fairly regularly in modern orthopedic practice. The pathophysiology of the disorder has been extensively described and is well known to physicians who care for patients with musculoskeletal injuries. The diagnosis, however, is often difficult to make. In this article, we review the clinical risk factors of acute compartment syndrome of the lower extremity, identify the current concepts of diagnosis and discuss appropriate treatment plans. We also describe the Canadian medicolegal environment in regard to compartment syndrome of the lower extremity. PMID:20858378
Multiple-Sensor Discrimination of Closely-Spaced Objects on a Ballistic Trajectory
2015-05-18
Nominal System Architecture ..................................................................................... 8 2 Simulation Environment... architecture ........................................................................................... 8 Figure 2. Simulation environment developed...uncertainty band for one or multiple sensors within the observation architecture . Resolving targets from one sensor image to another can prove difficult
Two centuries of extreme events over the Baltic Sea and North Sea regions
NASA Astrophysics Data System (ADS)
Stendel, Martin; den Besselaar Else, van; Abdel, Hannachi; Jaak, Jaagus; Elizabeth, Kent; Christiana, Lefebvre; Gudrun, Rosenhagen; Anna, Rutgersson; Frederik, Schenk; der Schrier Gerard, van; Tim, Woolings
2017-04-01
Two centuries of extreme events over the Baltic Sea and North Sea regions In the framework of the BACC 2 (for the Baltic Sea) and NOSCCA projects (for the North Sea region), studies of past and present variability and changes in atmospheric variables within the North Sea region over the instrumental period (roughly the past 200 years) have been investigated. Findings on trends in temperature and precipitation have already been presented. Here we focus on data homogeneity issues and examine how reliable reanalyses are in this context. Unlike most other regions in the world, there is a wealth of old observations available for the Baltic and North Sea regions, most of it in handwritten form in meteorological journals and other publications. These datasets need to be carefully digitised and homogenized. For this, a thorough quality control must be applied; otherwise the digitised datasets may prove useless or even counterproductive. We present evidence that this step cannot be conducted without human interference and thus cannot be fully automated. Furthermore, inhomogeneities due to e.g. instrumentation and station relocations need to be addressed. A wealth of reanalysis products is available, which can help detect such inhomogeneities in observed time series, but at the same time are prone to biases and/or spurious trends themselves e.g. introduced by changes in the availability and quality of the underlying assimilated data. It therefore in general remains unclear in how far we can simulate the pre-satellite era with respect to homogeneity with reanalyses based only on parts of the observing system. Extreme events and changes in extreme situations are more important and of greater (societal) significance than changes in mean climate. However, changes in extreme weather events are difficult to assess not only because they are, per definition, rare events, but also due to the homogeneity issues outlined above. Taking these into account, we present evidence for changes in extrema in the Baltic and North Sea regions. In particular, we will discuss different measures of storminess, compare the persistence of circulation types and investigate to what extent atmospheric circulation over the Baltic and North Sea regions is controlled influenced by distant factors, in particular Arctic sea-ice decline in recent decades.
ERIC Educational Resources Information Center
Dean, John F.
For a variety of reasons, collection care in Southeast Asia, especially in the northern regions, is fraught with many difficult challenges. Climates that are unfriendly to paper-based materials, poor economies, war, and civil unrest, are just a few of the reasons that librarians and archivists find it extremely difficult to ensure the survival of…
Effect of loudness on reaction time and response force in different motor tasks.
Jaśkowski, Piotr; Włodarczyk, Dariusz
2005-12-01
Van der Molen and Keuss, in 1979 and 1981, showed that paradoxically long reaction times occur with extremely strong auditory stimuli when the task is difficult, e.g., choice-by-location or Simon paradigm. It was argued that this paradoxical behavior of RT is due to active inhibition of an arousal-dependent bypassing mechanism to prevent false responses. As the peak force, i.e., maximal force exerted by participants on a response key, is considered to be related to immediate arousal, we predicted that for extremely loud stimuli and for difficult tasks, lengthening of RT should be associated with reduction of peak force. Moreover, these effects should be enhanced when emphasis is on accuracy rather than speed. Although the relation between RT and intensity depended on task difficulty, no increase in RT was found for the loudest tones. Moreover, peak force increased monotonically with loudness, showing no tendency to be suppressed for loudest tones and difficult tasks.
Characterizing uncertain sea-level rise projections to support investment decisions.
Sriver, Ryan L; Lempert, Robert J; Wikman-Svahn, Per; Keller, Klaus
2018-01-01
Many institutions worldwide are considering how to include uncertainty about future changes in sea-levels and storm surges into their investment decisions regarding large capital infrastructures. Here we examine how to characterize deeply uncertain climate change projections to support such decisions using Robust Decision Making analysis. We address questions regarding how to confront the potential for future changes in low probability but large impact flooding events due to changes in sea-levels and storm surges. Such extreme events can affect investments in infrastructure but have proved difficult to consider in such decisions because of the deep uncertainty surrounding them. This study utilizes Robust Decision Making methods to address two questions applied to investment decisions at the Port of Los Angeles: (1) Under what future conditions would a Port of Los Angeles decision to harden its facilities against extreme flood scenarios at the next upgrade pass a cost-benefit test, and (2) Do sea-level rise projections and other information suggest such conditions are sufficiently likely to justify such an investment? We also compare and contrast the Robust Decision Making methods with a full probabilistic analysis. These two analysis frameworks result in similar investment recommendations for different idealized future sea-level projections, but provide different information to decision makers and envision different types of engagement with stakeholders. In particular, the full probabilistic analysis begins by aggregating the best scientific information into a single set of joint probability distributions, while the Robust Decision Making analysis identifies scenarios where a decision to invest in near-term response to extreme sea-level rise passes a cost-benefit test, and then assembles scientific information of differing levels of confidence to help decision makers judge whether or not these scenarios are sufficiently likely to justify making such investments. Results highlight the highly-localized and context dependent nature of applying Robust Decision Making methods to inform investment decisions.
Characterizing uncertain sea-level rise projections to support investment decisions
Lempert, Robert J.; Wikman-Svahn, Per; Keller, Klaus
2018-01-01
Many institutions worldwide are considering how to include uncertainty about future changes in sea-levels and storm surges into their investment decisions regarding large capital infrastructures. Here we examine how to characterize deeply uncertain climate change projections to support such decisions using Robust Decision Making analysis. We address questions regarding how to confront the potential for future changes in low probability but large impact flooding events due to changes in sea-levels and storm surges. Such extreme events can affect investments in infrastructure but have proved difficult to consider in such decisions because of the deep uncertainty surrounding them. This study utilizes Robust Decision Making methods to address two questions applied to investment decisions at the Port of Los Angeles: (1) Under what future conditions would a Port of Los Angeles decision to harden its facilities against extreme flood scenarios at the next upgrade pass a cost-benefit test, and (2) Do sea-level rise projections and other information suggest such conditions are sufficiently likely to justify such an investment? We also compare and contrast the Robust Decision Making methods with a full probabilistic analysis. These two analysis frameworks result in similar investment recommendations for different idealized future sea-level projections, but provide different information to decision makers and envision different types of engagement with stakeholders. In particular, the full probabilistic analysis begins by aggregating the best scientific information into a single set of joint probability distributions, while the Robust Decision Making analysis identifies scenarios where a decision to invest in near-term response to extreme sea-level rise passes a cost-benefit test, and then assembles scientific information of differing levels of confidence to help decision makers judge whether or not these scenarios are sufficiently likely to justify making such investments. Results highlight the highly-localized and context dependent nature of applying Robust Decision Making methods to inform investment decisions. PMID:29414978
NASA Astrophysics Data System (ADS)
Cucchi, Marco; Petitta, Marcello; Calmanti, Sandro
2016-04-01
High temperatures have an impact on the energy balance of any living organism and on the operational capabilities of critical infrastructures. Heat-wave indicators have been mainly developed with the aim of capturing the potential impacts on specific sectors (agriculture, health, wildfires, transport, power generation and distribution). However, the ability to capture the occurrence of extreme temperature events is an essential property of a multi-hazard extreme climate indicator. Aim of this study is to develop a standardized heat-wave indicator, that can be combined with other indices in order to describe multiple hazards in a single indicator. The proposed approach can be used in order to have a quantified indicator of the strenght of a certain extreme. As a matter of fact, extremes are usually distributed in exponential or exponential-exponential functions and it is difficult to quickly asses how strong was an extreme events considering only its magnitude. The proposed approach simplify the quantitative and qualitative communication of extreme magnitude
Bondability of ipê (Tabebuia spp.) wood using ambient-curing exterior wood adhesives
Daniel J. Yelle
2016-01-01
Ipê is an extremely difficult species to bond because of its high density, interlocking grain, and high volumetric swellingâshrinkage under prolonged wet conditions. Despite its difficulties, the wood is known to be extremely durable in exterior conditions because of its resistance to microbial and insect degradation. Therefore, investigating its bondability with...
The Extreme Ultraviolet Explorer science instruments development - Lessons learned
NASA Technical Reports Server (NTRS)
Malina, Roger F.; Battel, S.
1991-01-01
The science instruments development project for the Extreme Ultraviolet Explorer (EUVE) satellite is reviewed. Issues discussed include the philosophical basis of the program, the establishment of a tight development team, the approach to planning and phasing activities, the handling of the most difficult technical problems, and the assessment of the work done during the preimplemntation period of the project.
Detection and recognition of uneaten fish food pellets in aquaculture using image processing
NASA Astrophysics Data System (ADS)
Liu, Huanyu; Xu, Lihong; Li, Dawei
2015-03-01
The waste of fish food has always been a serious problem in aquaculture. On one hand, the leftover fish food spawns a big waste in the aquaculture industry because fish food accounts for a large proportion of the investment. On the other hand, the left over fish food may pollute the water and make fishes sick. In general, the reason for fish food waste is that there is no feedback about the consumption of delivered fish food after feeding. So it is extremely difficult for fish farmers to determine the amount of feedstuff that should be delivered each time and the feeding intervals. In this paper, we propose an effective method using image processing techniques to solve this problem. During feeding events, we use an underwater camera with supplementary LED lights to obtain images of uneaten fish food pellets on the tank bottom. An algorithm is then developed to figure out the number of left pellets using adaptive Otsu thresholding and a linear-time component labeling algorithm. This proposed algorithm proves to be effective in handling the non-uniform lighting and very accurate number of pellets are counted in experiments.
Unstructured CFD Aerodynamic Analysis of a Generic UCAV Configuration
NASA Technical Reports Server (NTRS)
Frink, Neal T.; Tormalm, Magnus; Schmidt, Stefan
2011-01-01
Three independent studies from the United States (NASA), Sweden (FOI), and Australia (DSTO) are analyzed to assess the state of current unstructured-grid computational fluid dynamic tools and practices for predicting the complex static and dynamic aerodynamic and stability characteristics of a generic 53-degree swept, round-leading-edge uninhabited combat air vehicle configuration, called SACCON. NASA exercised the USM3D tetrahedral cell-centered flow solver, while FOI and DSTO applied the FOI/EDGE general-cell vertex-based solver. The authors primarily employ the Reynolds Averaged Navier-Stokes (RANS) assumption, with a limited assessment of the EDGE Detached Eddy Simulation (DES) extension, to explore sensitivities to grids and turbulence models. Correlations with experimental data are provided for force and moments, surface pressure, and off-body flow measurements. The vortical flow field over SACCON proved extremely difficult to model adequately. As a general rule, the prospect of obtaining reasonable correlations of SACCON pitching moment characteristics with the RANS formulation is not promising, even for static cases. Yet, dynamic pitch oscillation results seem to produce a promising characterization of shapes for the lift and pitching moment hysteresis curves. Future studies of this configuration should include more investigation with higher-fidelity turbulence models, such as DES.
Clean Power Generation from the Intractable Natural Coalfield Fires: Turn Harm into Benefit.
Shi, Bobo; Su, Hetao; Li, Jinshi; Qi, Haining; Zhou, Fubao; Torero, José L; Chen, Zhongwei
2017-07-13
The coal fires, a global catastrophe for hundreds of years, have been proved extremely difficult to control, and hit almost every coal-bearing area globally. Meanwhile, underground coal fires contain tremendous reservoir of geothermal energy. Approximately one billion tons of coal burns underground annually in the world, which could generate ~1000 GW per annum. A game-changing approach, environmentally sound thermal energy extraction from the intractable natural coalfield fires, is being developed by utilizing the waste energy and reducing the temperature of coalfield fires at the same time. Based on the Seebeck effect of thermoelectric materials, the temperature difference between the heat medium and cooling medium was employed to directly convert thermal energy into clean electrical energy. By the time of December 2016, the power generation from a single borehole at Daquan Lake fire district in Xinjiang has been exceeded 174.6 W. The field trial demonstrates that it is possible to exploit and utilize the waste heat resources in the treated coal fire areas. It promises a significant impact on the structure of global energy generation and can also promote progress in thermoelectric conversion materials, geothermal exploration, underground coal fires control and other energy related areas.
The medically important aerobic actinomycetes: epidemiology and microbiology.
McNeil, M M; Brown, J M
1994-01-01
The aerobic actinomycetes are soil-inhabiting microorganisms that occur worldwide. In 1888, Nocard first recognized the pathogenic potential of this group of microorganisms. Since then, several aerobic actinomycetes have been a major source of interest for the commercial drug industry and have proved to be extremely useful microorganisms for producing novel antimicrobial agents. They have also been well known as potential veterinary pathogens affecting many different animal species. The medically important aerobic actinomycetes may cause significant morbidity and mortality, in particular in highly susceptible severely immunocompromised patients, including transplant recipients and patients infected with human immunodeficiency virus. However, the diagnosis of these infections may be difficult, and effective antimicrobial therapy may be complicated by antimicrobial resistance. The taxonomy of these microorganisms has been problematic. In recent revisions of their classification, new pathogenic species have been recognized. The development of additional and more reliable diagnostic tests and of a standardized method for antimicrobial susceptibility testing and the application of molecular techniques for the diagnosis and subtyping of these microorganisms are needed to better diagnose and treat infected patients and to identify effective control measures for these unusual pathogens. We review the epidemiology and microbiology of the major medically important aerobic actinomycetes. Images PMID:7923055
Promoting Active Learning: The Use of Computational Software Programs
NASA Astrophysics Data System (ADS)
Dickinson, Tom
The increased emphasis on active learning in essentially all disciplines is proving beneficial in terms of a student's depth of learning, retention, and completion of challenging courses. Formats labeled flipped, hybrid and blended facilitate face-to-face active learning. To be effective, students need to absorb a significant fraction of the course material prior to class, e.g., using online lectures and reading assignments. Getting students to assimilate and at least partially understand this material prior to class can be extremely difficult. As an aid to achieving this preparation as well as enhancing depth of understanding, we find the use of software programs such as Mathematica®or MatLab®, very helpful. We have written several Mathematica®applications and student exercises for use in a blended format two semester E&M course. Formats include tutorials, simulations, graded and non-graded quizzes, walk-through problems, exploration and interpretation exercises, and numerical solutions of complex problems. A good portion of this activity involves student-written code. We will discuss the efficacy of these applications, their role in promoting active learning, and the range of possible uses of this basic scheme in other classes.
Wilson, Kate E; Marouga, Rita; Prime, John E; Pashby, D Paul; Orange, Paul R; Crosier, Steven; Keith, Alexander B; Lathe, Richard; Mullins, John; Estibeiro, Peter; Bergling, Helene; Hawkins, Edward; Morris, Christopher M
2005-10-01
Comparative proteomic methods are rapidly being applied to many different biological systems including complex tissues. One pitfall of these methods is that in some cases, such as oncology and neuroscience, tissue complexity requires isolation of specific cell types and sample is limited. Laser microdissection (LMD) is commonly used for obtaining such samples for proteomic studies. We have combined LMD with sensitive thiol-reactive saturation dye labelling of protein samples and 2-D DIGE to identify protein changes in a test system, the isolated CA1 pyramidal neurone layer of a transgenic (Tg) rat carrying a human amyloid precursor protein transgene. Saturation dye labelling proved to be extremely sensitive with a spot map of over 5,000 proteins being readily produced from 5 mug total protein, with over 100 proteins being significantly altered at p < 0.0005. Of the proteins identified, all showed coherent changes associated with transgene expression. It was, however, difficult to identify significantly different proteins using PMF and MALDI-TOF on gels containing less than 500 mug total protein. The use of saturation dye labelling of limiting samples will therefore require the use of highly sensitive MS techniques to identify the significantly altered proteins isolated using methods such as LMD.
The attitudes of neonatal nurses towards extremely preterm infants.
Gallagher, Katie; Marlow, Neil; Edgley, Alison; Porock, Davina
2012-08-01
The paper is a report of a study of the attitudes of neonatal nurses towards extremely preterm infants. Alongside advancing survival at extremely preterm gestational ages, ethical debates concerning the provision of invasive care have proliferated in light of the high morbidity. Despite nurses being the healthcare professionals who work closest with the infant and their family, their potential influence is usually ignored when determining how parents come to decisions about future care for their extremely premature infant. A Q methodology was employed to explore the attitudes of neonatal nurses towards caring for extremely preterm infants. Data were collected between 2007 and 2008 and analysed using PQMethod and Card Content Analysis. Thirty-six nurses from six neonatal units in the United Kingdom participated. Although there was consensus around the professional role of the nurse, when faced with the complexities of neonatal nursing three distinguishing factors emerged: the importance of parental choice in decision-making, the belief that technology should be used to assess response to treatment, and the belief that healthcare professionals should undertake difficult decisions. Neonatal nurses report unexpected difficulties in upholding their professionally defined role through highly complex and ever varied decision-making processes. Recognition of individual attitudes to the care of extremely preterm infants and the role of the family in the face of difficult decisions should facilitate more open communication between the nurse and the parents and improve the experience of both the nurse and the family during these emotional situations. © 2011 Blackwell Publishing Ltd.
ERIC Educational Resources Information Center
Waters, W. G., II
1973-01-01
Analyzes the urban transport problems in comparison with those involved in a journey to the Moon. Indicates that the problem of enabling man to travel through the inner space of conurbations may prove to be more difficult than the transport problem of space travel. (CC)
Symmetry enhancement of extremal horizons in D = 5 supergravity
NASA Astrophysics Data System (ADS)
Kayani, U.
2018-06-01
We consider the near-horizon geometry of supersymmetric extremal black holes in un-gauged and gauged 5-dimensional supergravity, coupled to abelian vector multiplets. By analyzing the global properties of the Killing spinors, we prove that the near-horizon geometries undergo a supersymmetry enhancement. This follows from a set of generalized Lichnerowicz-type theorems we establish, together with an index theory argument. As a consequence, these solutions always admit a symmetry group.
USDA-ARS?s Scientific Manuscript database
Forage nutritive value (i.e., forage quality) impacts livestock health and performance, but determining the quality of forages for grazing animals is difficult. In the 1970s, development and application of bench-top near-infrared spectroscopy (NIRS) techniques to assess forage quality proved to be ...
Development of DNA Microarrays for Metabolic Pathway and Bioprocess Monitoring
DOE Office of Scientific and Technical Information (OSTI.GOV)
Gregory Stephanopoulos
Transcriptional profiling experiments utilizing DNA microarrays to study the intracellular accumulation of PHB in Synechocystis has proved difficult in large part because strains that show significant differences in PHB which would justify global analysis of gene expression have not been isolated.
Predictive Model of Systemic Toxicity (SOT)
In an effort to ensure chemical safety in light of regulatory advances away from reliance on animal testing, USEPA and L’Oréal have collaborated to develop a quantitative systemic toxicity prediction model. Prediction of human systemic toxicity has proved difficult and remains a ...
Setting Environmental Standards
ERIC Educational Resources Information Center
Fishbein, Gershon
1975-01-01
Recent court decisions have pointed out the complexities involved in setting environmental standards. Environmental health is composed of multiple causative agents, most of which work over long periods of time. This makes the cause-and-effect relationship between health statistics and environmental contaminant exposures difficult to prove in…
Quality versus quantity: The complexities of quality of life determinations for neonatal nurses.
Green, Janet; Darbyshire, Philip; Adams, Anne; Jackson, Debra
2017-11-01
The ability to save the life of an extremely premature baby has increased substantially over the last decade. This survival, however, can be associated with unfavourable outcomes for both baby and family. Questions are now being asked about quality of life for survivors of extreme prematurity. Quality of life is rightly deemed to be an important consideration in high technology neonatal care; yet, it is notoriously difficult to determine or predict. How does one define and operationalise what is considered to be in the best interest of a surviving extremely premature baby, especially when the full extent of the outcomes might not be known for several years? The research investigates the caregiving dilemmas often faced by neonatal nurses when caring for extremely premature babies. This article explores the issues arising for neonatal nurses when they considered the philosophical and ethical questions about quality of life in babies ≤24 weeks gestation. Data were collected via a questionnaire to Australian neonatal nurses and semi-structured interviews with 24 neonatal nurses in New South Wales, Australia. Ethical considerations: Ethical processes and procedures have been adhered to by the researchers. A qualitative approach was used to analyse the data. The theme 'difficult choices' was generated which comprised three sub-themes: 'damaged through survival', 'the importance of the brain' and 'families are important'. The results show that neonatal nurses believed that quality of life was an important consideration; yet they experienced significant inner conflict and uncertainty when asked to define or suggest specific elements of quality of life, or to suggest how it might be determined. It was even more difficult for the nurses to say when an extremely premature baby's life possessed quality. Their previous clinical and personal experiences led the nurses to believe that the quality of the family's life was important, and possibly more so than the quality of life of the surviving baby. This finding contrasts markedly with much of the existing literature in this field. Quality of life for extremely premature babies was an important consideration for neonatal nurses; however, they experienced difficulty deciding how to operationalise such considerations in their everyday clinical practice.
Consistent interactive segmentation of pulmonary ground glass nodules identified in CT studies
NASA Astrophysics Data System (ADS)
Zhang, Li; Fang, Ming; Naidich, David P.; Novak, Carol L.
2004-05-01
Ground glass nodules (GGNs) have proved especially problematic in lung cancer diagnosis, as despite frequently being malignant they characteristically have extremely slow rates of growth. This problem is further magnified by the small size of many of these lesions now being routinely detected following the introduction of multislice CT scanners capable of acquiring contiguous high resolution 1 to 1.25 mm sections throughout the thorax in a single breathhold period. Although segmentation of solid nodules can be used clinically to determine volume doubling times quantitatively, reliable methods for segmentation of pure ground glass nodules have yet to be introduced. Our purpose is to evaluate a newly developed computer-based segmentation method for rapid and reproducible measurements of pure ground glass nodules. 23 pure or mixed ground glass nodules were identified in a total of 8 patients by a radiologist and subsequently segmented by our computer-based method using Markov random field and shape analysis. The computer-based segmentation was initialized by a click point. Methodological consistency was assessed using the overlap ratio between 3 segmentations initialized by 3 different click points for each nodule. The 95% confidence interval on the mean of the overlap ratios proved to be [0.984, 0.998]. The computer-based method failed on two nodules that were difficult to segment even manually either due to especially low contrast or markedly irregular margins. While achieving consistent manual segmentation of ground glass nodules has proven problematic most often due to indistinct boundaries and interobserver variability, our proposed method introduces a powerful new tool for obtaining reproducible quantitative measurements of these lesions. It is our intention to further document the value of this approach with a still larger set of ground glass nodules.
NASA Astrophysics Data System (ADS)
Lavers, David A.; Pappenberger, Florian; Richardson, David S.; Zsoter, Ervin
2016-11-01
In winter, heavy precipitation and floods along the west coasts of midlatitude continents are largely caused by intense water vapor transport (integrated vapor transport (IVT)) within the atmospheric river of extratropical cyclones. This study builds on previous findings that showed that forecasts of IVT have higher predictability than precipitation, by applying and evaluating the European Centre for Medium-Range Weather Forecasts Extreme Forecast Index (EFI) for IVT in ensemble forecasts during three winters across Europe. We show that the IVT EFI is more able (than the precipitation EFI) to capture extreme precipitation in forecast week 2 during forecasts initialized in a positive North Atlantic Oscillation (NAO) phase; conversely, the precipitation EFI is better during the negative NAO phase and at shorter leads. An IVT EFI example for storm Desmond in December 2015 highlights its potential to identify upcoming hydrometeorological extremes, which may prove useful to the user and forecasting communities.
Analytical and experimental evaluation of an aluminum bridge deck panel. Part 2, failure analysis.
DOT National Transportation Integrated Search
1999-01-01
Aluminum bridge decks may prove to be an alternative to concrete decks for improving the performance of structural bridge systems. Combining excellent corrosion resistance with extremely low density, aluminum decks can prolong surface life, facilitat...
Angular-momentum--mass inequality for axisymmetric black holes.
Dain, Sergio
2006-03-17
The inequality square root J
1993-04-01
features such as electronic flight controls, blown flaps, winglets , and head-up displays proved more difficult than the contractor had estimated.’ To...air’ifter designed to provide the full range of strategic and tactical airlift capability. This blend of capabilities will enable it to carry outsize
Distant Galaxy Clusters Hosting Extreme Central Galaxies
NASA Astrophysics Data System (ADS)
McDonald, Michael
2014-09-01
The recently-discovered Phoenix cluster harbors the most star-forming central cluster galaxy of any cluster in the known Universe, by nearly a factor of 10. This extreme system appears to be fulfilling early cooling flow predictions, although the lack of similar systems makes any interpretation difficult. In an attempt to find other "Phoenix-like" clusters, we have cross-correlated archival all-sky surveys (in which Phoenix was detected) and isolated 4 similarly-extreme systems which are also coincident in position and redshift with an overdensity of red galaxies. We propose here to obtain Chandra observations of these extreme, Phoenix-like systems, in order to confirm them as relaxed, rapidly-cooling galaxy clusters.
Mucci, Viviana
2018-01-01
Chest ultrasonography (CU) is a noninvasive imaging technique able to provide an immediate diagnosis of the underlying aetiology of acute respiratory failure and traumatic chest injuries. Given the great technologies, it is now possible to perform accurate CU in remote and adverse environments including the combat field, extreme sport settings, and environmental disasters, as well as during space missions. Today, the usage of CU in the extreme emergency setting is more likely to occur, as this technique proved to be a fast diagnostic tool to assist resuscitation manoeuvres and interventional procedures in many cases. A scientific literature review is presented here. This was based on a systematic search of published literature, on the following online databases: PubMed and Scopus. The following words were used: “chest sonography,” “ thoracic ultrasound,” and “lung sonography,” in different combinations with “extreme sport,” “extreme environment,” “wilderness,” “catastrophe,” and “extreme conditions.” This manuscript reports the most relevant usages of CU in the extreme setting as well as technological improvements and current limitations. CU application in the extreme setting is further encouraged here. PMID:29736195
To the fringe and back: Violent extremism and the psychology of deviance.
Kruglanski, Arie W; Jasko, Katarzyna; Chernikova, Marina; Dugas, Michelle; Webber, David
2017-04-01
We outline a general psychological theory of extremism and apply it to the special case of violent extremism (VE). Extremism is defined as motivated deviance from general behavioral norms and is assumed to stem from a shift from a balanced satisfaction of basic human needs afforded by moderation to a motivational imbalance wherein a given need dominates the others. Because motivational imbalance is difficult to sustain, only few individuals do, rendering extreme behavior relatively rare, hence deviant. Thus, individual dynamics translate into social patterns wherein majorities of individuals practice moderation, whereas extremism is the province of the few. Both extremism and moderation require the ability to successfully carry out the activities that these demand. Ability is partially determined by the activities' difficulty, controllable in part by external agents who promote or oppose extremism. Application of this general framework to VE identifies the specific need that animates it and offers broad guidelines for addressing this pernicious phenomenon. (PsycINFO Database Record (c) 2017 APA, all rights reserved).
Identifying Opportunities for Vertical Integration of Biochemistry and Clinical Medicine.
Wendelberger, Karen J.; Burke, Rebecca; Haas, Arthur L.; Harenwattananon, Marisa; Simpson, Deborah
1998-01-01
Objectives: Retention of basic science knowledge, as judged by National Board of Medical Examiners' (NBME) data, suffers due to lack of apparent relevance and isolation of instruction from clinical application, especially in biochemistry. However, the literature reveals no systematic process for identifying key biochemical concepts and associated clinical conditions. This study systematically identified difficult biochemical concepts and their common clinical conditions as a critical step towards enhancing relevance and retention of biochemistry.Methods: A multi-step/ multiple stakeholder process was used to: (1) identify important biochemistry concepts; (2) determine students' perceptions of concept difficulty; (3) assess biochemistry faculty, student, and clinical teaching scholars' perceived relevance of identified concepts; and (4) identify associated common clinical conditions for relevant and difficult concepts. Surveys and a modified Delphi process were used to gather data, subsequently analyzed using SPSS for Windows.Results: Sixteen key biochemical concepts were identified. Second year medical students rated 14/16 concepts as extremely difficult while fourth year students rated nine concepts as moderately to extremely difficult. On average, each teaching scholar generated common clinical conditions for 6.2 of the 16 concepts, yielding a set of seven critical concepts and associated clinical conditions.Conclusions: Key stakeholders in the instructional process struggle to identify biochemistry concepts that are critical, difficult to learn and associated with common clinical conditions. However, through a systematic process beginning with identification of concepts and associated clinical conditions, relevance of basic science instruction can be enhanced.
Patients whom neurologists find difficult to help
Carson, A; Stone, J; Warlow, C; Sharpe, M
2004-01-01
Objective: To test the hypothesis that patients whose symptoms were less explained by organic disease would be perceived as more difficult to help. Methods: In a consecutive series of 300 new neurology outpatients, neurologists indicated on four point Likert-type scales how "difficult to help" they found the patient and to what extent the patient's symptoms were explained by organic disease. The patients' demographics, health status, number of somatic symptoms, and mental state were also assessed. Results: The neurologists rated 143 patients (48%) as "not at all difficult" to help, 111 (37%) as "somewhat difficult", 27 (9%) as "very difficult", and 18 (6%) as "extremely difficult". A logistic regression model was constructed and the hypothesis that patients whose symptoms were less explained by organic disease would be perceived as more difficult to help was supported. The only other measured variable that contributed to perceived difficulty was physical disability, but it explained only a small amount of the variance. Conclusions: Neurologists find patients whose symptoms are not explained by organic disease more difficult to help than their other patients. PMID:15548505
Federal Register 2010, 2011, 2012, 2013, 2014
2011-09-09
... Proclamation Every day, hard-working men and women across America prove that, even in difficult times, our... we commit to supporting their efforts in moving our economy forward. The right to organize and... Americans today are given opportunities because their parents and grandparents fought for these basic rights...
Getting More out of Team Projects: Incentivizing Leadership to Enhance Performance
ERIC Educational Resources Information Center
Ferrante, Claudia J.; Green, Steve G.; Forster, William R.
2006-01-01
This study addresses changes in student perceptions when team leaders are incentivized. Although the benefits of groupwork have been thoroughly studied and documented, minimizing dysfunctional teamwork may prove difficult because of leadership incentives, social loafing, and organizational justice implications. Using an innovative pedagogical…
The Episodic Nature of Episodic-Like Memories
ERIC Educational Resources Information Center
Easton, Alexander; Webster, Lisa A. D.; Eacott, Madeline J.
2012-01-01
Studying episodic memory in nonhuman animals has proved difficult because definitions in humans require conscious recollection. Here, we assessed humans' experience of episodic-like recognition memory tasks that have been used with animals. It was found that tasks using contextual information to discriminate events could only be accurately…
Du, Y; Zhao, L-J; Xu, Q; Wu, K-H; Deng, H-W
2017-05-01
Low bone mineral density (BMD) and osteoporosis have become a public health problem. We found that non-Hispanic white, black, and Asian adults with extremely low education and personal income are more likely to have lower BMD. This relationship is gender-specific. These findings are valuable to guide bone health interventions. The evidence is limited regarding the relationship between socioeconomic status (SES) and bone mineral density (BMD) for minority populations in the USA, as well as the relationship between SES and BMD for men. This study explored and examined the relationship between SES and BMD by race/ethnicity and gender. Data (n = 6568) from the Louisiana Osteoporosis Study (LOS) was examined, including data for non-Hispanic whites (n = 4153), non-Hispanic blacks (n = 1907), and non-Hispanic Asians (n = 508). General linear models were used to estimate the relationship of SES and BMD (total hip and lumbar spine) stratified by race/ethnicity and gender. Adjustments were made for physiological and behavioral factors. After adjusting for covariates, men with education levels below high school graduate experienced relatively low hip BMD than their counterparts with college or graduate education (p < 0.05). In addition, women reporting a personal annual income under $20,000 had relatively low hip and spine BMD than their counterparts with higher income level(s) (p < 0.05). Establishing a conclusive positive or negative association between BMD and SES proved to be difficult. However, individuals who are at an extreme SES disadvantage are the most vulnerable to have relatively low BMD in the study population. Efforts to promote bone health may benefit from focusing on men with low education levels and women with low individual income.
On the dimension of complex responses in nonlinear structural vibrations
NASA Astrophysics Data System (ADS)
Wiebe, R.; Spottswood, S. M.
2016-07-01
The ability to accurately model engineering systems under extreme dynamic loads would prove a major breakthrough in many aspects of aerospace, mechanical, and civil engineering. Extreme loads frequently induce both nonlinearities and coupling which increase the complexity of the response and the computational cost of finite element models. Dimension reduction has recently gained traction and promises the ability to distill dynamic responses down to a minimal dimension without sacrificing accuracy. In this context, the dimensionality of a response is related to the number of modes needed in a reduced order model to accurately simulate the response. Thus, an important step is characterizing the dimensionality of complex nonlinear responses of structures. In this work, the dimensionality of the nonlinear response of a post-buckled beam is investigated. Significant detail is dedicated to carefully introducing the experiment, the verification of a finite element model, and the dimensionality estimation algorithm as it is hoped that this system may help serve as a benchmark test case. It is shown that with minor modifications, the method of false nearest neighbors can quantitatively distinguish between the response dimension of various snap-through, non-snap-through, random, and deterministic loads. The state-space dimension of the nonlinear system in question increased from 2-to-10 as the system response moved from simple, low-level harmonic to chaotic snap-through. Beyond the problem studied herein, the techniques developed will serve as a prescriptive guide in developing fast and accurate dimensionally reduced models of nonlinear systems, and eventually as a tool for adaptive dimension-reduction in numerical modeling. The results are especially relevant in the aerospace industry for the design of thin structures such as beams, panels, and shells, which are all capable of spatio-temporally complex dynamic responses that are difficult and computationally expensive to model.
Successful Space Flight of High-Speed InGaAs Photodiode Onboard the International Space Station
NASA Technical Reports Server (NTRS)
Joshi, Abhay; Prasad, Narasimha; Datta, Shubbashish
2017-01-01
Photonic systems are required for several space applications, including satellite communication links and lidar sensors. Although such systems are ubiquitous in terrestrial applications, deployment in space requires the constituent components to withstand extreme environmental conditions, including wide operating temperature range, mechanical shock and vibration, and radiation. These conditions are significantly more stringent than alternative standards, namely Bellcore GR-468 and MIL-STD 883, which may be satisfied by typical, commercially available, photonic components. Furthermore, it is very difficult to simultaneously reproduce several aspects of space environment, including exposure to galactic cosmic rays (GCR), in a laboratory. Therefore, it is necessary to operate key photonic components in space to achieve a technology readiness level of 7 and beyond. Accordingly, the International Space Station (ISS) provides an invaluable test bed for qualifying such components for space missions. We present a fiber-pigtailed photodiode module, having a -3 dB bandwidth of 16.8 GHz, that survived 18 months on the ISS as part of the Materials International Space Station Experiment (MISSE) 7 mission. This module was launched by NASA Langley Research Center on November 16, 2009 on the Space Shuttle Atlantis (STS-129), as part of their lidar transceiver components. While orbiting on the ISS in a passive experiment container, the photodiode module was exposed to extreme temperature cycling from -157 degrees Celsius to +121 degrees Celsius 16 times a day, proton radiation from the inner Van Allen belt at the South Atlantic Anomaly, and galactic cosmic rays. The module returned to Earth on the Space Shuttle Endeavor (STS-134) on June 1, 2011 for further characterization. The post flight test of the photodiode module, shown in Fig. 1a, demonstrates no change in the module's performance, thus proving its survivability during launch and in space environment.
A fire danger rating system for Hawaii
Robert E. Burgan; Francis M. Fujioka; George H. Hirata
1974-01-01
Extremes in rainfall on the Hawaiian Islands make it difficult to judge forest fire danger conditions. The use of an automatic data collection and computer processing system helps to monitor the problem.
Zhang, Zhi-Hai; Gao, Ling-Xiao; Guo, Yuan-Jun; Wang, Wei; Mo, Xiang-Xia
2012-12-01
The template selection is essential in the application of digital micromirror spectrometer. The best theoretical coding H-matrix is not widely used due to acyclic, complex coding and difficult achievement. The noise ratio of best practical S-matrix for improvement is slightly inferior to matrix H. So we designed a new type complementary S-matrix. Through studying its noise improvement theory, the algorithm is proved to have the advantages of both H-matrix and S-matrix. The experiments proved that the SNR can be increased 2.05 times than S-template.
Market Orientation and Its Measurement in Universities
ERIC Educational Resources Information Center
Niculescu, Mihai; Xu, Bing; Hampton, Gerald M.; Peterson, Robin T.
2013-01-01
Historically, the measurement of market orientation has proved to be difficult, due to the low external validity of the concept. Existing scales exhibit acceptable properties in measuring market orientation in business organizations, but are less accurate in the context of higher education institutions. This paper compares the performance of three…
Therapeutic Process and Outcome: The Interplay of Research
ERIC Educational Resources Information Center
Campbel, Holly
2008-01-01
From Freud through to modern times researchers have aimed to develop a clearer understanding of therapeutic processes and outcomes. Despite this continued interest in the field, the representation of psychotherapy processes and the applicability of research findings and recommendations to the therapeutic field continue to prove difficult.…
[Rituals of birth in Senegal].
Ba, Idrissa; Diodo Ly, Oumou; Rizzi, Alice Titia; Sandri, Rosella; Thiam, Mamadou Habib
In a Senegalese society undergoing profound change, holding on to certain beliefs and social and cultural practices can sometimes prove difficult. Prevention and care systems must take into account social and cultural representations in order to support these families as best as possible. Copyright © 2017 Elsevier Masson SAS. All rights reserved.
On the Reform of Russian Education
ERIC Educational Resources Information Center
Mironov, V. V.
2013-01-01
The "modernization" of Russian education is linked to the functioning of the entire social system of Russia, and reforms are proving difficult and contradictory. The use of the Unified State Examination in Russia, plus participation in the Bologna process, is causing concern about the ability of education to meet the needs of the…
EVALUATION OF EXTRACTION AND SPECTROSCOPIC METHODS FOR PB SPECIATION IN AN AMENDED SOIL
Immobilization of pyromorphite (Pbs(PO4hCI) via P amendments to Pb contaminated soils is proving to be a viable method of remediation. However, the issue of ascertaining the amount of soil Pb converted to pyromorphite is difficult in heterogeneous soil systems. Previous attempts ...
Transient Structured Distance as a Maneuver in Marital Therapy
ERIC Educational Resources Information Center
Greene, Bernard L.; And Others
1973-01-01
Experience with 73 cases has shown the value of Transient Structured Distance as a maneuver in marriage therapy. While the TSD is a radical form of intervention with risks of anxiety reactions, homosexual panic, or divorce, it has proved effective with difficult forms of acute or chronic marital disharmony. (Author)
The Small College Enrollment Officer: Relationship Marketing at Work
ERIC Educational Resources Information Center
Vander Schee, Brian A.
2010-01-01
Prospective college students regularly read in promotional literature that the college experience is personal and unique to each individual. However, if their experience in the recruitment process proves otherwise it is difficult to convince students that they can each have a personal relationship with the institution. Small colleges can overcome…
Using Computer-Assisted Multiple Representations in Learning Geometry Proofs
ERIC Educational Resources Information Center
Wong, Wing-Kwong; Yin, Sheng-Kai; Yang, Hsi-Hsun; Cheng, Ying-Hao
2011-01-01
Geometry theorem proving involves skills that are difficult to learn. Instead of working with abstract and complicated representations, students might start with concrete, graphical representations. A proof tree is a graphical representation of a formal proof, with each node representing a proposition or given conditions. A computer-assisted…
Teaching Linear Algebra: Must the Fog Always Roll In?
ERIC Educational Resources Information Center
Carlson, David
1993-01-01
Proposes methods to teach the more difficult concepts of linear algebra. Examines features of the Linear Algebra Curriculum Study Group Core Syllabus, and presents problems from the core syllabus that utilize the mathematical process skills of making conjectures, proving the results, and communicating the results to colleagues. Presents five…
Laboratory Experiments for Undergraduate Instruction in Economics.
ERIC Educational Resources Information Center
Wells, Donald A.
1991-01-01
Describes the generation and use of experimental data in teaching economics. Includes a double oral auction experiment and a monopoly pricing experiment. Concludes that such experiments allow the instructor to see what the students have learned, how they reason, and what parts of the material have proved difficult. (DK)
NASA Technical Reports Server (NTRS)
Anderson, R. E.; Carlson, A. W.; Lewis, J.
1977-01-01
Helical VHF antenna mounts on roof of moving vehicle to communicate with distant stations via earth satellites. Antenna requires no pointing and can provide two-way communication while vehicle moves at high speed. Device has proved extremely successful in electrocardiogram transmission tests between medical services vehicle and hospital emergency room.
Management of stormwater facility maintenance residuals
DOT National Transportation Integrated Search
1998-06-01
Current research on stormwater maintenance residuals has revealed that the source and nature of these materials is extremely variable, that regulation can be ambiguous, and handling can be costly and difficult. From a regulatory perspective, data ind...
Countering Extremism; Beyond Interagency Cooperation
2011-04-18
such as health care, education and welfare for its constituents. Hizballah also garnered credit in Lebanon for forcing Israel to withdraw in... Minster , will likely make the official relationship with the GOL significantly more difficult. 24 “A
NASA Astrophysics Data System (ADS)
Dougan, Lorna
2015-11-01
Wherever we look on Earth - even in the most inhospitable places - we find life. But how do organisms manage to survive such difficult conditions? Lorna Dougan explains how physicists are helping to unravel the properties of “extremophile” life.
Goold, Imogen; Maslen, Hannah
2015-01-01
Increasing interest in the use of cognitive enhancing pharmaceuticals, such as modafinil, has led to considerable ethical debate about issues around authenticity, fairness and even whether there is a moral obligation to enhance. This latter question has raised questions as to whether there might be a legal obligation to enhance. We have argued elsewhere that the law will not oblige a professional to self-enhance. In this article, we explore a second reason why a claim of negligence for a failure to enhance would be unlikely to succeed: the problem of establishing causation. As the science on enhancers and what they are capable of currently stands, it would be almost invariably impossible to establish a causal link between failure to enhance to redress fatigue, and the harm that allegedly resulted. Even where a link between fatigue and harm can be established, it will be extremely difficult to show that taking an enhancer would have averted the harm. We focus on the most likely context in which such claims might arise--clinical negligence--and on the most efficacious enhancing drug currently available-modafinil. © The Author 2014. Published by Oxford University Press; all rights reserved. For Permissions, please email: journals.permissions@oup.com.
Thalassemia and malaria: new insights into an old problem.
Clegg, J B; Weatherall, D J
1999-01-01
The hemoglobinopathies are probably the world's most common genetic diseases: The World Health Organization has estimated that at least 5% of the population are carriers for one or other of the most serious forms, the alpha- and beta-thalassemias and the structural variant hemoglobins S, C, and E, which are found at polymorphic frequencies in many countries. All these hemoglobinopathies are believed to provide protection against malaria, and it is thought that, in malarial regions of the world, natural selection has been responsible for elevating and maintaining their gene frequencies, an idea first proposed 50 years ago by J.B.S. Haldane. Epidemiological studies undertaken in the 1950s on hemoglobin S in Africa provided support for the "malaria hypothesis," but until recently it has proved extremely difficult to verify it for the thalassemias. The application of molecular methods has, however, provided new opportunities to address this old question. Population and molecular genetic analysis of thalassemia variants, and microepidemiological studies of the relationship between alpha-thalassemia and malaria in the southwest Pacific, have provided unequivocal evidence for protection. Surprisingly, some of this protection appears to derive from enhanced susceptibility in very young thalassemic children to both Plasmodium falciparum and, especially, P. vivax, and this early exposure appears to provide the basis for better protection in later life.
Improved LCI profile of LAB based on latest technology advances
DOE Office of Scientific and Technical Information (OSTI.GOV)
Berna, J.L.; Renta, C.
1995-12-31
The first technology used to produce LAB was introduced in the early 60`s and since then a continuous optimization process has taken place on this highly competitive product on which additional cost effectiveness improvements became highly challenging. The latest technology introduced in the market (CEPSA {minus} UOP DETAL) based on a fixed bed alkylation process, has already been proved on a commercial scale. The simplicity of the new technology as compared to current ones, namely HF, has proven to be very effective in reducing substantially the impact due to several major components of the Life Cycle Inventory (LCI) in particularmore » the emissions of the overall operation. Additional improvements in other aspects like energy consumption are extremely difficult to achieve today as this parameter has already been highly optimized during the last two decades making in fact LAB a highly effective chemical in terms of energy requirements as well as on raw material consumption. The results of the first LCI of the new LAB technology indicate a reduction of CO process emissions to nearly 1/2 as compared to standard HF process as well as reduction in solid waste to 1/3 of the corresponding HF process. Important reductions have also been noticed on NOx emissions with the new technology.« less
Computation of pattern invariance in brain-like structures.
Ullman, S; Soloviev, S
1999-10-01
A fundamental capacity of the perceptual systems and the brain in general is to deal with the novel and the unexpected. In vision, we can effortlessly recognize a familiar object under novel viewing conditions, or recognize a new object as a member of a familiar class, such as a house, a face, or a car. This ability to generalize and deal efficiently with novel stimuli has long been considered a challenging example of brain-like computation that proved extremely difficult to replicate in artificial systems. In this paper we present an approach to generalization and invariant recognition. We focus our discussion on the problem of invariance to position in the visual field, but also sketch how similar principles could apply to other domains.The approach is based on the use of a large repertoire of partial generalizations that are built upon past experience. In the case of shift invariance, visual patterns are described as the conjunction of multiple overlapping image fragments. The invariance to the more primitive fragments is built into the system by past experience. Shift invariance of complex shapes is obtained from the invariance of their constituent fragments. We study by simulations aspects of this shift invariance method and then consider its extensions to invariant perception and classification by brain-like structures.
Association between foot type and tibial stress injuries: a systematic review.
Barnes, A; Wheat, J; Milner, C
2008-02-01
To systematically review published articles investigating the association between structural foot characteristics and tibial stress injuries, and to suggest possible future avenues of research in this area. Literature was identified, selected and appraised in accordance with the methods of a systematic review. Articles potentially relevant to the research question were identified by searching the following electronic databases: Amed, Cinahl, Index to UK theses, Medline, PubMed, Scopus, Sports discus and Web of science. Duplicates were removed and, based on the title and abstract, the full text of relevant studies were retrieved. Two reviewers independently assessed papers; this formed the basis for the inclusion of the most appropriate trials. From the 479 articles originally identified, nine were deemed appropriate for inclusion in the review. In general, specific data relating to this relationship was limited. Outcomes of the nine investigations were difficult to compare due to differing methods used across studies. Results have proved conflicting, with limited evidence found to implicate any specific foot type as a potential risk factor for tibial stress injuries. No definitive conclusions can be drawn relating foot structure or function to an increased risk of tibial stress injuries. Extremes of foot types are likely to pose an increased risk of tibial stress injuries compared to normal arched feet.
Highlighting Astyanax Species Diversity through DNA Barcoding
Oliveira, Carlos Alexandre Miranda; de Melo, Filipe Augusto Gonçalves; Bertaco, Vinicius de Araújo; de Astarloa, Juan M. Díaz; Rosso, Juan J.; Foresti, Fausto; Oliveira, Claudio
2016-01-01
DNA barcoding has been used extensively to solve taxonomic questions and identify new species. Neotropical fishes are found in a wide variety of shapes and sizes, with a large number of species yet to be described, many of which are very difficult to identify. Characidae is the most species-rich family of the Characiformes, and many of its genera are affected by taxonomic uncertainties, including the widely-distributed, species-rich genus Astyanax. In this study, we present an extensive analysis of Astyanax covering almost its entire area of occurrence, based on DNA barcoding. The use of different approaches (ABGD, GMYC and BIN) to the clustering of the sequences revealed ample consistency in the results obtained by the initial cutoff value of 2% divergence for putative species in the Neighbor-Joining analysis using the Kimura-2-parameter model. The results indicate the existence of five Astyanax lineages. Some groups, such as that composed by the trans-Andean forms, are mostly composed of well-defined species, and in others a number of nominal species are clustered together, hampering the delimitation of species, which in many cases proved impossible. The results confirm the extreme complexity of the systematics of the genus Astyanax and show that DNA barcoding can be an useful tool to address these complexes questions. PMID:27992537
Evolutionary-Optimized Photonic Network Structure in White Beetle Wing Scales.
Wilts, Bodo D; Sheng, Xiaoyuan; Holler, Mirko; Diaz, Ana; Guizar-Sicairos, Manuel; Raabe, Jörg; Hoppe, Robert; Liu, Shu-Hao; Langford, Richard; Onelli, Olimpia D; Chen, Duyu; Torquato, Salvatore; Steiner, Ullrich; Schroer, Christian G; Vignolini, Silvia; Sepe, Alessandro
2018-05-01
Most studies of structural color in nature concern periodic arrays, which through the interference of light create color. The "color" white however relies on the multiple scattering of light within a randomly structured medium, which randomizes the direction and phase of incident light. Opaque white materials therefore must be much thicker than periodic structures. It is known that flying insects create "white" in extremely thin layers. This raises the question, whether evolution has optimized the wing scale morphology for white reflection at a minimum material use. This hypothesis is difficult to prove, since this requires the detailed knowledge of the scattering morphology combined with a suitable theoretical model. Here, a cryoptychographic X-ray tomography method is employed to obtain a full 3D structural dataset of the network morphology within a white beetle wing scale. By digitally manipulating this 3D representation, this study demonstrates that this morphology indeed provides the highest white retroreflection at the minimum use of material, and hence weight for the organism. Changing any of the network parameters (within the parameter space accessible by biological materials) either increases the weight, increases the thickness, or reduces reflectivity, providing clear evidence for the evolutionary optimization of this morphology. © 2017 The Authors. Published by WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Communicating Storm Surge Forecast Uncertainty
NASA Astrophysics Data System (ADS)
Troutman, J. A.; Rhome, J.
2015-12-01
When it comes to tropical cyclones, storm surge is often the greatest threat to life and property along the coastal United States. The coastal population density has dramatically increased over the past 20 years, putting more people at risk. Informing emergency managers, decision-makers and the public about the potential for wind driven storm surge, however, has been extremely difficult. Recently, the Storm Surge Unit at the National Hurricane Center in Miami, Florida has developed a prototype experimental storm surge watch/warning graphic to help communicate this threat more effectively by identifying areas most at risk for life-threatening storm surge. This prototype is the initial step in the transition toward a NWS storm surge watch/warning system and highlights the inundation levels that have a 10% chance of being exceeded. The guidance for this product is the Probabilistic Hurricane Storm Surge (P-Surge) model, which predicts the probability of various storm surge heights by statistically evaluating numerous SLOSH model simulations. Questions remain, however, if exceedance values in addition to the 10% may be of equal importance to forecasters. P-Surge data from 2014 Hurricane Arthur is used to ascertain the practicality of incorporating other exceedance data into storm surge forecasts. Extracting forecast uncertainty information through analyzing P-surge exceedances overlaid with track and wind intensity forecasts proves to be beneficial for forecasters and decision support.
Hall, R. J.; Nogales, E.; Glaeser, R. M.
2011-01-01
The use of a Zernike-type phase plate in biological cryo-electron microscopy allows the imaging, without using defocus, of what are predominantly phase objects. It is thought that such phase-plate implementations might result in higher quality images, free from the problems of CTF correction that occur when images must be recorded at extremely high values of defocus. In single-particle cryo-electron microscopy it is hoped that these improvements in image quality will facilitate work on structures that have proved difficult to study, either because of their relatively small size or because the structures are not completely homogeneous. There is still a need, however, to quantify how much improvement can be gained by using a phase plate for single-particle cryo-electron microscopy. We present a method for quantitatively modelling the images recorded with 200 keV electrons, for single particles embedded in vitreous ice. We then investigate what difference the use of a phase-plate device could have on the processing of single-particle data. We confirm that using a phase plate results in single-particle datasets in which smaller molecules can be detected, particles can be more accurately aligned and problems of heterogeneity can be more easily addressed. PMID:21463690
NASA Astrophysics Data System (ADS)
Zhang, Yin; Xia, Jun; She, Dunxian
2018-01-01
In recent decades, extreme precipitation events have been a research hotspot worldwide. Based on 12 extreme precipitation indices, the spatiotemporal variation and statistical characteristic of precipitation extremes in the middle reaches of the Yellow River Basin (MRYRB) during 1960-2013 were investigated. The results showed that the values of most extreme precipitation indices (except consecutive dry days (CDD)) increased from the northwest to the southeast of the MRYRB, reflecting that the southeast was the wettest region in the study area. Temporally, the precipitation extremes presented a drying trend with less frequent precipitation events. Generalized extreme value (GEV) distribution was selected to fit the time series of all indices, and the quantiles values under the 50-year return period showed a similar spatial extent with the corresponding precipitation extreme indices during 1960-2013, indicating a higher risk of extreme precipitation in the southeast of the MRYRB. Furthermore, the changes in probability distribution functions of indices for the period of 1960-1986 and 1987-2013 revealed a drying tendency in our study area. Both El Niño-Southern Oscillation (ENSO) and Pacific Decadal Oscillation (PDO) were proved to have a strong influence on precipitation extremes in the MRYRB. The results of this study are useful to master the change rule of local precipitation extremes, which will help to prevent natural hazards caused.
Impact of extreme precipitation events in the Miño-Sil river basin
NASA Astrophysics Data System (ADS)
Fernández-González, Manuel; Añel, Juan Antonio; de la Torre, Laura
2015-04-01
We herein research the impact of extreme rainfall events in the Miño-Sil basin, a heavily dammed basin located in the northwestern Iberian Peninsula. Extreme rainfall events are very important in this basin because with 106 dams it is the most dammed in Spain. These dams are almost exclusively used for hydropower generation, the installed generating capacity reaches more than 2700 MW and represents almost 9% of the total installed electrical generation capacity of the Iberian Peninsula, therefore with a potential impact on the energy market. We research the extreme events of rainfall an their return periods trying to reproduce the past extreme events of rainfall and their time periods to prove the proper functioning of the adapted model, so we can forecast future extreme events of rainfall in the basin. This research tries to optimize the storage of dams and adapt the management to problems as climate change. The results obtained are very relevant for hydroelectric generation because the operation of hydropower system depends primarily on the availability of storaged water.
Soft-Tissue Injuries Associated With High-Energy Extremity Trauma: Principles of Management.
Norris; Kellam
1997-01-01
The management of high-energy extremity trauma has evolved over the past several decades, and appropriate treatment of associated soft-tissue injuries has proved to be an important factor in achieving a satisfactory outcome. Early evaluation of the severely injured extremity is crucial. Severe closed injuries require serial observation of the soft tissues and early skeletal stabilization. Open injuries require early aggressive debridement of the soft tissues followed by skeletal stabilization. Temporary wound dressings should remain in place until definitive soft-tissue coverage has been obtained. Definitive soft-tissue closure will be expedited by serial debridements performed every 48 to 72 hours in a sterile environment. Skeletal union is facilitated by early bone grafting and/or modification of the stabilizing device. Aggressive rehabilitation, includ-ing early social reintegration, are crucial for a good functional outcome. Adherence to protocols is especially beneficial in the management of salvageable severely injured extremities.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Dain, Sergio; Max Planck Institute for Gravitational Physics
2010-11-15
We present a formula that relates the variations of the area of extreme throat initial data with the variation of an appropriate defined mass functional. From this expression we deduce that the first variation, with fixed angular momentum, of the area is zero and the second variation is positive definite evaluated at the extreme Kerr throat initial data. This indicates that the area of the extreme Kerr throat initial data is a minimum among this class of data. And hence the area of generic throat initial data is bounded from below by the angular momentum. Also, this result strongly suggestsmore » that the inequality between area and angular momentum holds for generic asymptotically flat axially symmetric black holes. As an application, we prove this inequality in the nontrivial family of spinning Bowen-York initial data.« less
Re-Casting the U.S.-Mexico Border Security Net
2014-03-01
the best fence money can buy , and they counter us with a 2,500-year-old technology.214 The incident proved that these organizations are extremely...created a demand that has attracted illicit activity. DTOs have expanded their franchises to increase the size of their profits. Border security
NASA Technical Reports Server (NTRS)
1983-01-01
The power factor controller (PFC) senses shifts in the relationship between voltage and current, and matches them with a motor's need. This prevents waste as motors do not need a high voltage when they are not operating at full load conditions. PFC is manufactured by Nordic Controls Company, among others, and has proved extremely cost effective.
Extremal functions for singular Trudinger-Moser inequalities in the entire Euclidean space
NASA Astrophysics Data System (ADS)
Li, Xiaomeng; Yang, Yunyan
2018-04-01
In a previous work (Adimurthi and Yang, 2010 [2]), Adimurthi-Yang proved a singular Trudinger-Moser inequality in the entire Euclidean space RN (N ≥ 2). Precisely, if 0 ≤ β < 1 and 0 < γ ≤ 1 - β, then there holds for any τ > 0,
ERIC Educational Resources Information Center
Nist, J.S.
Specialists in the field of children's literature, who publish research and decide on awards for individual books, should give serious study to what children themselves choose to read. Among the children's books that were not originally awarded top honors by critics but that have proved extremely popular with children are the Oz books by L. Frank…
Federal Register 2010, 2011, 2012, 2013, 2014
2013-08-20
... rule is extremely difficult due to the numerous variables associated with delivery (e.g., weather... 2 hours resulting from weather or unforeseen construction delays. NRMCA claims that these frequent...
DeGregoris, Gerard; Diwan, Sudhir
2010-01-01
Lower back and extremity pain in the amputee patient can be challenging to classify and treat. Radicular compression in a patient with lower limb amputation may present as or be superimposed upon phantom limb pain, creating diagnostic difficulties. Both patients and physicians classically find it difficult to discern phantom sensation from phantom limb pain and stump pain; radicular compression is often not considered. Many studies have shown back pain to be a significant cause of pain in lower limb amputees, but sciatica has been rarely reported in amputees. We present a case of L4/5 radiculitis in an above-knee amputee presenting as phantom radiculitis. Our patient is a 67 year old gentleman with new onset 10/10 pain in a phantom extremity superimposed upon a 40 year history of previously stable phantom limb pain. MRI showed a central disc herniation at L4/5 with compression of the traversing left L4 nerve root. Two fluoroscopically guided left transforaminal epidural steroid injections at the level of the L4 and L5 spinal nerve roots totally alleviated his new onset pain. At one year post injection, his phantom radiculitis pain was completely gone, though his underlying phantom limb pain remained. Lumbar radiculitis in lower extremity amputee patients may be difficult to differentiate from baseline phantom limb pain. When conservative techniques fail, fluoroscopically guided spinal nerve injection may be valuable in determining the etiology of lower extremity pain. Our experience supports the notion that epidural steroid injections can effectively treat phantom lumbar radiculitis in lower extremity amputees.
Time on Your Hands: Modeling Time
ERIC Educational Resources Information Center
Finson, Kevin; Beaver, John
2007-01-01
Building physical models relative to a concept can be an important activity to help students develop and manipulate abstract ideas and mental models that often prove difficult to grasp. One such concept is "time". A method for helping students understand the cyclical nature of time involves the construction of a Time Zone Calculator through a…
DOT National Transportation Integrated Search
2010-11-01
Increasing seat belt usage in the United States has proved to be a : slow and difficult task. It has taken about 30 years since NHTSA : conducted the first seat belt and child restraint workshops in : 1978 to reach 84% usage in 2009. In general, seat...
Free Speech, Quality Control, and Flame Wars
ERIC Educational Resources Information Center
Leary, Patrick; Labanowski, Jan K.; Korenman, Joan
2007-01-01
The authors who happened to be moderators of academic online discussions bring tales from the trenches. Whether it's computational chemistry, the history of the book, or women's studies, the technology and the users can both prove difficult. The first author talks about two scholarly discussion lists. SHARP-L, whose name comes from the Society for…
ERIC Educational Resources Information Center
Adams, Benjamin Thomas
2012-01-01
Places and place types, such as "small town", play a fundamental role in how people organize knowledge about the world. Although places are commonly referenced in human communication, often they are not canonically defined and many of the properties people associate with them have proved difficult to operationalize. In information…
Strategy Instruction in Listening for Lower-Intermediate Learners of French
ERIC Educational Resources Information Center
Graham, Suzanne; Macaro, Ernesto
2008-01-01
Second language listening has historically proved to be a difficult skill. Strategy instruction studies have sought to bring about improvements in subjects' listening but with mixed results. This lack of success might be due to the nature of listening strategy theory and its influence on conceptualizations of listening strategy instruction. The…
Gaining Ground in Understanding the Play-Literacy Relationship
ERIC Educational Resources Information Center
Roskos, Kathleen A.; Christie, James F.
2013-01-01
Many in the field of early literacy development and learning believe strongly that play and literacy share common ground, but they have found the idea difficult to prove. While some primary research indicates a positive relationship, the impact of play seems to occur at different levels of development, which complicates how researchers view its…
Using Group Work to Develop Intercultural Skills in the Accounting Curriculum in Australia
ERIC Educational Resources Information Center
Daly, Anne; Hoy, Simon; Hughes, Mark; Islam, Jesmin; Mak, Anita S.
2015-01-01
This paper reports on the processes and outcomes of an experiential learning intervention designed to improve intercultural skills in accounting students by building cross-cultural alliances in culturally mixed groups. The cultural backgrounds of students in accounting units are diverse, and it has proved difficult to break down barriers to…
USDA-ARS?s Scientific Manuscript database
Breeding for resistance to downy mildew in hop has proved difficult presumably because of the highly quantitative nature of genetic control over expression with environment playing a large role in determining phenotype. We hypothesize that eliminating environmental influences over the expression of...
Direct-seedling pines in the south
Harold J. Derr; William F. Mann
1971-01-01
Direct seeding of the southern pines is a versatile reforestation technique that is being widely accepted by land managers. On many sites it is more economical than planting nursery-grown seedlings or waiting for natural reproduction. It is applicable on some sites where access, terrain, or drainage conditions make planting difficult. Commercial trials have proved it...
3 CFR 8707 - Proclamation 8707 of September 2, 2011. Labor Day, 2011
Code of Federal Regulations, 2012 CFR
2012-01-01
..., hard-working men and women across America prove that, even in difficult times, our country is still... supporting their efforts in moving our economy forward. The right to organize and collectively bargain is a... given opportunities because their parents and grandparents fought for these basic rights and values. The...
Rhipicephalus microplus strain Deutsch, 10 BAC clone sequences
USDA-ARS?s Scientific Manuscript database
The cattle tick, Rhipicephalus (Boophilus) microplus, has a genome over 2.4 times the size of the human genome, and with over 70% of repetitive DNA, this genome would prove very costly to sequence at today's prices and difficult to assemble and analyze. We used labeled DNA probes from the coding reg...
Rhipicephalus microplus strain Deutsch, whole genome shotgun sequencing project Version 2
USDA-ARS?s Scientific Manuscript database
The cattle tick, Rhipicephalus (Boophilus) microplus, has a genome over 2.4 times the size of the human genome, and with over 70% of repetitive DNA, this genome would prove very costly to sequence at today's prices and difficult to assemble and analyze. Cot filtration/selection techniques were used ...
Perirenal lipoma versus renal cell carcinoma.
Mydlo, J H; Shore, N; Reuter, V; Herr, H W
1991-07-01
Pure renal and perirenal lipomas are rare. They arise from renal cortex, capsule, or perirenal tissue, and may be difficult to distinguish from renal adenocarcinomas. We report on a patient who presented with a renal mass that had the radiologic findings suggestive of a renal cell carcinoma, but proved to be a simple lipoma.
ERIC Educational Resources Information Center
Ryder, Nuala; Leinonen, Eeva; Schulz, Joerg
2008-01-01
Background: Pragmatic language impairment in children with specific language impairment has proved difficult to assess, and the nature of their abilities to comprehend pragmatic meaning has not been fully investigated. Aims: To develop both a cognitive approach to pragmatic language assessment based on Relevance Theory and an assessment tool for…
ERIC Educational Resources Information Center
Schachter, Ron
2010-01-01
When Adam Fletcher was hired as the student engagement specialist for Washington state's education department 10 years ago, it didn't take him long to realize how difficult his newly created job would prove. Fletcher said no one was talking about the roles of students other than as learners, and they laughed out loud at the proposal of students…
Workers with Disabilities and the Challenges of Emotional Labour
ERIC Educational Resources Information Center
Wilton, Robert D.
2008-01-01
This paper explores the implications of emotional labour for workers with disabilities, drawing on qualitative data from interviews with 59 respondents who had disabilities and who worked in service sector occupations. The analysis illustrates that employer demands for emotional labour may prove difficult for workers with a range of disabilities,…
The Discussion Section as Argument: The Language Used to Prove Knowledge Claims
ERIC Educational Resources Information Center
Parkinson, Jean
2011-01-01
Writing the Discussion section of a laboratory report or dissertation is difficult for students to master. It involves complex causal, conditional and purposive argument; this argument guides the reader from acceptance of the relatively uncontroversial data to acceptance of the writer's knowledge claim. Students benefit therefore if they are…
Learning about Seasons: A Guide for Teachers and Curriculum Developers
ERIC Educational Resources Information Center
Sneider, Cary; Bar, Varda; Kavanagh, Claudine
2011-01-01
The video "A Private Universe" evokes surprise and dismay among educators and scientists by demonstrating that even the brightest students fail to grasp a seemingly simple and fundamental concept--the reason for seasons. This literature review describes the findings of 41 studies that collectively illustrate why the concept proves difficult to…
Extremes in ecology: Avoiding the misleading effects of sampling variation in summary analyses
Link, W.A.; Sauer, J.R.
1996-01-01
Surveys such as the North American Breeding Bird Survey (BBS) produce large collections of parameter estimates. One's natural inclination when confronted with lists of parameter estimates is to look for the extreme values: in the BBS, these correspond to the species that appear to have the greatest changes in population size through time. Unfortunately, extreme estimates are liable to correspond to the most poorly estimated parameters. Consequently, the most extreme parameters may not match up with the most extreme parameter estimates. The ranking of parameter values on the basis of their estimates are a difficult statistical problem. We use data from the BBS and simulations to illustrate the potential misleading effects of sampling variation in rankings of parameters. We describe empirical Bayes and constrained empirical Bayes procedures which provide partial solutions to the problem of ranking in the presence of sampling variation.
NASA Astrophysics Data System (ADS)
Van de Moortel, Maxime
2018-05-01
We show non-linear stability and instability results in spherical symmetry for the interior of a charged black hole—approaching a sub-extremal Reissner-Nordström background fast enough—in presence of a massive and charged scalar field, motivated by the strong cosmic censorship conjecture in that setting: 1. Stability We prove that spherically symmetric characteristic initial data to the Einstein-Maxwell-Klein-Gordon equations approaching a Reissner-Nordström background with a sufficiently decaying polynomial decay rate on the event horizon gives rise to a space-time possessing a Cauchy horizon in a neighbourhood of time-like infinity. Moreover, if the decay is even stronger, we prove that the space-time metric admits a continuous extension to the Cauchy horizon. This generalizes the celebrated stability result of Dafermos for Einstein-Maxwell-real-scalar-field in spherical symmetry. 2. Instability We prove that for the class of space-times considered in the stability part, whose scalar field in addition obeys a polynomial averaged- L 2 (consistent) lower bound on the event horizon, the scalar field obeys an integrated lower bound transversally to the Cauchy horizon. As a consequence we prove that the non-degenerate energy is infinite on any null surface crossing the Cauchy horizon and the curvature of a geodesic vector field blows up at the Cauchy horizon near time-like infinity. This generalizes an instability result due to Luk and Oh for Einstein-Maxwell-real-scalar-field in spherical symmetry. This instability of the black hole interior can also be viewed as a step towards the resolution of the C 2 strong cosmic censorship conjecture for one-ended asymptotically flat initial data.
Arctic sea ice, Eurasia snow, and extreme winter haze in China.
Zou, Yufei; Wang, Yuhang; Zhang, Yuzhong; Koo, Ja-Ho
2017-03-01
The East China Plains (ECP) region experienced the worst haze pollution on record for January in 2013. We show that the unprecedented haze event is due to the extremely poor ventilation conditions, which had not been seen in the preceding three decades. Statistical analysis suggests that the extremely poor ventilation conditions are linked to Arctic sea ice loss in the preceding autumn and extensive boreal snowfall in the earlier winter. We identify the regional circulation mode that leads to extremely poor ventilation over the ECP region. Climate model simulations indicate that boreal cryospheric forcing enhances the regional circulation mode of poor ventilation in the ECP region and provides conducive conditions for extreme haze such as that of 2013. Consequently, extreme haze events in winter will likely occur at a higher frequency in China as a result of the changing boreal cryosphere, posing difficult challenges for winter haze mitigation but providing a strong incentive for greenhouse gas emission reduction.
Arctic sea ice, Eurasia snow, and extreme winter haze in China
Zou, Yufei; Wang, Yuhang; Zhang, Yuzhong; Koo, Ja-Ho
2017-01-01
The East China Plains (ECP) region experienced the worst haze pollution on record for January in 2013. We show that the unprecedented haze event is due to the extremely poor ventilation conditions, which had not been seen in the preceding three decades. Statistical analysis suggests that the extremely poor ventilation conditions are linked to Arctic sea ice loss in the preceding autumn and extensive boreal snowfall in the earlier winter. We identify the regional circulation mode that leads to extremely poor ventilation over the ECP region. Climate model simulations indicate that boreal cryospheric forcing enhances the regional circulation mode of poor ventilation in the ECP region and provides conducive conditions for extreme haze such as that of 2013. Consequently, extreme haze events in winter will likely occur at a higher frequency in China as a result of the changing boreal cryosphere, posing difficult challenges for winter haze mitigation but providing a strong incentive for greenhouse gas emission reduction. PMID:28345056
Durable nonslip stainless-steel drivebelts
NASA Technical Reports Server (NTRS)
Bahiman, H.
1979-01-01
Two toothed stainless-steel drive belt retains its strength and flexibility in extreme heat or cold, intense radiation, or under high loading. Belt does not stretch or slip and is particularly suited to machinery for which replacement is difficult or impossible.
Extremality of Gaussian quantum states.
Wolf, Michael M; Giedke, Geza; Cirac, J Ignacio
2006-03-03
We investigate Gaussian quantum states in view of their exceptional role within the space of all continuous variables states. A general method for deriving extremality results is provided and applied to entanglement measures, secret key distillation and the classical capacity of bosonic quantum channels. We prove that for every given covariance matrix the distillable secret key rate and the entanglement, if measured appropriately, are minimized by Gaussian states. This result leads to a clearer picture of the validity of frequently made Gaussian approximations. Moreover, it implies that Gaussian encodings are optimal for the transmission of classical information through bosonic channels, if the capacity is additive.
Rosetta Structure Prediction as a Tool for Solving Difficult Molecular Replacement Problems.
DiMaio, Frank
2017-01-01
Molecular replacement (MR), a method for solving the crystallographic phase problem using phases derived from a model of the target structure, has proven extremely valuable, accounting for the vast majority of structures solved by X-ray crystallography. However, when the resolution of data is low, or the starting model is very dissimilar to the target protein, solving structures via molecular replacement may be very challenging. In recent years, protein structure prediction methodology has emerged as a powerful tool in model building and model refinement for difficult molecular replacement problems. This chapter describes some of the tools available in Rosetta for model building and model refinement specifically geared toward difficult molecular replacement cases.
Risk assessment of precipitation extremes in northern Xinjiang, China
NASA Astrophysics Data System (ADS)
Yang, Jun; Pei, Ying; Zhang, Yanwei; Ge, Quansheng
2018-05-01
This study was conducted using daily precipitation records gathered at 37 meteorological stations in northern Xinjiang, China, from 1961 to 2010. We used the extreme value theory model, generalized extreme value (GEV) and generalized Pareto distribution (GPD), statistical distribution function to fit outputs of precipitation extremes with different return periods to estimate risks of precipitation extremes and diagnose aridity-humidity environmental variation and corresponding spatial patterns in northern Xinjiang. Spatiotemporal patterns of daily maximum precipitation showed that aridity-humidity conditions of northern Xinjiang could be well represented by the return periods of the precipitation data. Indices of daily maximum precipitation were effective in the prediction of floods in the study area. By analyzing future projections of daily maximum precipitation (2, 5, 10, 30, 50, and 100 years), we conclude that the flood risk will gradually increase in northern Xinjiang. GEV extreme value modeling yielded the best results, proving to be extremely valuable. Through example analysis for extreme precipitation models, the GEV statistical model was superior in terms of favorable analog extreme precipitation. The GPD model calculation results reflect annual precipitation. For most of the estimated sites' 2 and 5-year T for precipitation levels, GPD results were slightly greater than GEV results. The study found that extreme precipitation reaching a certain limit value level will cause a flood disaster. Therefore, predicting future extreme precipitation may aid warnings of flood disaster. A suitable policy concerning effective water resource management is thus urgently required.
An Optimal Algorithm towards Successive Location Privacy in Sensor Networks with Dynamic Programming
NASA Astrophysics Data System (ADS)
Zhao, Baokang; Wang, Dan; Shao, Zili; Cao, Jiannong; Chan, Keith C. C.; Su, Jinshu
In wireless sensor networks, preserving location privacy under successive inference attacks is extremely critical. Although this problem is NP-complete in general cases, we propose a dynamic programming based algorithm and prove it is optimal in special cases where the correlation only exists between p immediate adjacent observations.
Environmental risk assessment of Polish wastewater treatment plant activity.
Kudłak, Błażej; Wieczerzak, Monika; Yotova, Galina; Tsakovski, Stefan; Simeonov, Vasil; Namieśnik, Jacek
2016-10-01
Wastewater treatment plants (WWTPs) play an extremely important role in shaping modern society's environmental well-being and awareness, however only well operated and supervised systems can be considered as environmentally sustainable. For this reason, an attempt was undertaken to assess the environmental burden posed by WWTPs in major Polish cities by collecting water samples prior to and just after wastewater release points. Both classical and biological methods (Microtox(®), Ostracodtoxkit F™ and comet assay) were utilized to assess environmental impact of given WWTP. Interestingly, in some cases, water quality improvement indicated as a toxicity decrement toward one of the bio-indicating organisms makes water worse for others in the systems. This fact is particularly noticeable in case of Silesian cities where heavy industry and high population density is present. It proves that WWTP should undergo individual evaluation of pollutant removal efficiency and tuned to selectively remove pollutants of highest risk to surrounding regional ecosystems. Biotests again proved to be an extremely important tool to fully assess the impact of environmental stressors on water bodies receiving effluents from WWTPs. Copyright © 2016 Elsevier Ltd. All rights reserved.
7 CFR 989.159 - Regulation of the handling of raisins subsequent to their acquisition.
Code of Federal Regulations, 2012 CFR
2012-01-01
... Foods).” If shipment involves exportation to a foreign country, the handler shall surrender to the... failure to comply with all applicable food and sanitary rules and regulations of city, county, state... difficult, if not impossible, to prove the extent of such damage. Therefore, the handler shall pay to the...
7 CFR 989.159 - Regulation of the handling of raisins subsequent to their acquisition.
Code of Federal Regulations, 2014 CFR
2014-01-01
... Foods).” If shipment involves exportation to a foreign country, the handler shall surrender to the... failure to comply with all applicable food and sanitary rules and regulations of city, county, state... difficult, if not impossible, to prove the extent of such damage. Therefore, the handler shall pay to the...
7 CFR 989.159 - Regulation of the handling of raisins subsequent to their acquisition.
Code of Federal Regulations, 2013 CFR
2013-01-01
... Foods).” If shipment involves exportation to a foreign country, the handler shall surrender to the... failure to comply with all applicable food and sanitary rules and regulations of city, county, state... difficult, if not impossible, to prove the extent of such damage. Therefore, the handler shall pay to the...
ERIC Educational Resources Information Center
Castermans, Dries; Wilquet, Valerie; Steyaert, Jean; van de Ven, Wim; Fryns, Jean-Pierre; Devriendt, Koen
2004-01-01
We review the different strategies currently used to try to identify susceptibility genes for idiopathic autism. Although identification of genes is usually straightforward in Mendelian disorders, it has proved to be much more difficult to establish in polygenic disorders like autism. Neither genome screens of affected siblings nor the large…
ERIC Educational Resources Information Center
Maydeu-Olivares, Alberto; Hernandez, Adolfo
2007-01-01
The interpretation of a Thurstonian model for paired comparisons where the utilities' covariance matrix is unrestricted proved to be difficult due to the comparative nature of the data. We show that under a suitable constraint the utilities' correlation matrix can be estimated, yielding a readily interpretable solution. This set of identification…
Assisted Workouts: Starting My Own Workout Program
ERIC Educational Resources Information Center
Cousminer, Douglas
2003-01-01
As an undergraduate student with cerebral palsy, I found it difficult to achieve my goal of starting a regular exercise program at my school, the University of Central Florida. However, when I started a program called Assisted Workouts in spring 2003. the struggle proved to be well worth it. The program is not only beneficial to me, but it has…
Kinase-Mediated Regulation of 40S Ribosome Assembly in Human Breast Cancer
2017-02-01
Major Task 2 and Major Task 3 (i) CRISPR /cas9-deleted Ltv1-null TNBC clones that have been purified by Dr. Karbstein by growth in the presence of...cells using CRISPR /Cas9 technology proved difficult, as our hypothesis was correct, where Ltv1 is essential for proper growth of TNBC. In particular
ERIC Educational Resources Information Center
VanLehn, Kurt; Wetzel, Jon; Grover, Sachin; van de Sande, Brett
2017-01-01
Constructing models of dynamic systems is an important skill in both mathematics and science instruction. However, it has proved difficult to teach. Dragoon is an intelligent tutoring system intended to quickly and effectively teach this important skill. This paper describes Dragoon and an evaluation of it. The evaluation randomly assigned…
An Uncommon Approach to a Common Algebraic Error
ERIC Educational Resources Information Center
Rossi, Paul S.
2008-01-01
The basic rules of elementary algebra can often appear beyond the grasp of many students. Even though most subjects, including calculus, prove to be more difficult, it is the simple rules of algebra that continue to be the "thorn in the side" of many mathematics students. In this paper we present a result intended to help students achieve a…
Investigating the Extraordinary X-Ray Variability of the Infrared Quasar IRAS 13349+2439
NASA Technical Reports Server (NTRS)
Leighly, Karen M.
1999-01-01
We observed the luminous quasar IRAS 13349+2439 using RXTE (X Ray Timing Explorer) in order to search for rapid variability. Unfortunately, the source was in a low state during the observation (PCA count rate approximately 1 - 2 counts/s). It was therefore somewhat weak for RXTE and detailed analysis proved to be difficult.
Balancing Difference and the Common Good: Lessons from a Post-Conflict Society
ERIC Educational Resources Information Center
Gallagher, Tony
2005-01-01
Northern Ireland endured a quarter century of political violence from 1969 until the declaration of ceasefires in 1994. Although a political settlement was signed in 1998, the actual implementation of agreed institutions has proved to be very difficult and the actual institutions have been fragile (and are currently under suspension). The purpose…
The Quality and Results of Vocational Education by Correctional Institutions. Final Report.
ERIC Educational Resources Information Center
Rabinowitz, William; And Others
This study was undertaken to determine if variations in the quality of vocational education offered in prisons, and the skill level developed by participants in these programs, are related to the inmates' post-release adjustment. It proved difficult to execute the study as designed, and the collected data were neither as numerous nor as complete…
Gender Issues in Action Research: Implications for Adult Education
ERIC Educational Resources Information Center
Heiskanen, Tuula
2006-01-01
Gender equality is a widely recognized value. Still, on the practical level, it is not easy to achieve true gender equality. Gender has proved to be a complicated issue both for research and practice. Gender change projects trying to make changes in detected disadvantages have repeatedly run into a problem: it is difficult to put gender issues on…
Summer Fallowing Helps Establish Cottonwood on Old Fields
James B. Baker; B. G. Blackmon
1973-01-01
Cottonwood is an ideal crop for many old fields in the Mississippi Delta, but getting the trees established on these sites has proved difficult. Surface soils are often compacted and depleted of nutrients, and grasses and other herbaceous vegetation compete strongly with the young trees for moisture and nutrients. Fallowing in the summer before cottonwood cuttings are...
Reluctant Learners? Muslim Youth Confront the Holocaust
ERIC Educational Resources Information Center
Short, Geoffrey
2013-01-01
There is good reason to believe that anti-Semitism is rife in Muslim communities across the world. Consequently, one might expect that teaching the Holocaust in schools with a substantial Muslim presence would prove a difficult and stressful experience. In this article, I draw on a diverse body of literature to argue for a more nuanced approach to…
An Augustinian Culture of Learning for Interdisciplinary Honors Programs
ERIC Educational Resources Information Center
Ste. Antoine, Tom
2010-01-01
Any attempt to discern the purpose of honors education and to integrate it with the unique ethos of a Christian institution can prove to be difficult. Yet, describing and articulating a sense of purpose is essential for an honors program to justify itself. This essay contends that a philosophy of education based on Augustine's…
Understanding "Human" Waves: Exploiting the Physics in a Viral Video
ERIC Educational Resources Information Center
Ferrer-Roca, Chantal
2018-01-01
Waves are a relevant part of physics that students find difficult to grasp, even in those cases in which wave propagation kinematics can be visualized. This may hinder a proper understanding of sound, light or quantum physics phenomena that are explained using a wave model. So-called "human" waves, choreographed by people, have proved to…
Equipment modifications for perennial nutsedge control in fallow organic transition
USDA-ARS?s Scientific Manuscript database
Perennial nutsedges are extremely difficult to control in organic crop transition and production systems. Herbicides suitable for use in certified organic production do not adequately control perennial nutsedges. Cultural and mechanical control are partially effective in controlling perennial nuts...
Acupuncture and Deaf-Mutism--An Essay in Cross-Cultural Defectology
ERIC Educational Resources Information Center
Sutton, Andrew
1977-01-01
Describes reportedly successful treatment of deaf-mutes in China by acupuncture, and suggests that the disorders might have been more psychological than physical. The author comments that interpretation of poorly documented reports from unfamiliar cultures is extremely difficult. (AV)
NASA Technical Reports Server (NTRS)
Sater, B. L.; Riley, T. J.; Janssen, W.
1973-01-01
A hybrid microelectronics solid state relay was developed in a TO-116 package for the MINX project. The relay provides 2500 Vdc input to output isolation and operated from a MHTL logic signal to switch a load of 400 Vdc at 2 mA. The relay is designed to operate in space and survive 1000 thermal cycles of 120 C to 80 C. The use of X-rays for failure analysis in small hybrid circuits proved valuable and the applications of vacuum deposited Parylene as a dielectric coating proved extremely valuable.
Malignant solitary fibrous tumor in the extremity: Cytopathologic findings
Khanchel, Fatma; Driss, Maha; Mrad, Karima; Romdhane, Khaled Ben
2012-01-01
Malignant solitary fibrous tumor (SFT) is an extremely rare neoplasm. There are only rare published accounts of the cytopathologic features of this tumor. We report a case of a 59-year-old woman presented with a 10-year history of a right thigh mass. A preoperative fine needle aspiration (FNA) was performed. Smears were hypercellular, with cohesive and crowded tissue fragments, haphazard cell arrangements and many single cells. The tumor cells were polymorphous, plump spindled or round with often indented or bare nuclei. A differential diagnosis of low grade sarcoma was favored. The diagnosis of malignant SFT is extremely difficult on FNA and must be included in the differential diagnosis of spindle cell neoplasms. PMID:22787298
Evolution caused by extreme events.
Grant, Peter R; Grant, B Rosemary; Huey, Raymond B; Johnson, Marc T J; Knoll, Andrew H; Schmitt, Johanna
2017-06-19
Extreme events can be a major driver of evolutionary change over geological and contemporary timescales. Outstanding examples are evolutionary diversification following mass extinctions caused by extreme volcanism or asteroid impact. The evolution of organisms in contemporary time is typically viewed as a gradual and incremental process that results from genetic change, environmental perturbation or both. However, contemporary environments occasionally experience strong perturbations such as heat waves, floods, hurricanes, droughts and pest outbreaks. These extreme events set up strong selection pressures on organisms, and are small-scale analogues of the dramatic changes documented in the fossil record. Because extreme events are rare, almost by definition, they are difficult to study. So far most attention has been given to their ecological rather than to their evolutionary consequences. We review several case studies of contemporary evolution in response to two types of extreme environmental perturbations, episodic (pulse) or prolonged (press). Evolution is most likely to occur when extreme events alter community composition. We encourage investigators to be prepared for evolutionary change in response to rare events during long-term field studies.This article is part of the themed issue 'Behavioural, ecological and evolutionary responses to extreme climatic events'. © 2017 The Author(s).
Congenital Differences of the Upper Extremity: Classification and Treatment Principles
2011-01-01
For hand surgeons, the treatment of children with congenital differences of the upper extremity is challenging because of the diverse spectrum of conditions encountered, but the task is also rewarding because it provides surgeons with the opportunity to impact a child's growth and development. An ideal classification of congenital differences of the upper extremity would reflect the full spectrum of morphologic abnormalities and encompass etiology, a guide to treatment, and provide prognoses. In this report, I review current classification systems and discuss their contradictions and limitations. In addition, I present a modified classification system and provide treatment principles. As our understanding of the etiology of congenital differences of the upper extremity increases and as experience of treating difficult cases accumulates, even an ideal classification system and optimal treatment strategies will undoubtedly continue to evolve. PMID:21909463
Geographic patterns of networks derived from extreme precipitation over the Indian subcontinent
NASA Astrophysics Data System (ADS)
Stolbova, Veronika; Bookhagen, Bodo; Marwan, Norbert; Kurths, Juergen
2014-05-01
Complex networks (CN) and event synchronization (ES) methods have been applied to study a number of climate phenomena such as Indian Summer Monsoon (ISM), South-American Monsoon, and African Monsoon. These methods proved to be powerful tools to infer interdependencies in climate dynamics between geographical sites, spatial structures, and key regions of the considered climate phenomenon. Here, we use these methods to study the spatial temporal variability of the extreme rainfall over the Indian subcontinent, in order to filter the data by coarse-graining the network, and to identify geographic patterns that are signature features (spatial signatures) of the ISM. We find four main geographic patterns of networks derived from extreme precipitation over the Indian subcontinent using up-to-date satellite-derived, and high temporal and spatial resolution rain-gauge interpolated daily rainfall datasets. In order to prove that our results are also relevant for other climatic variables like pressure and temperature, we use re-analysis data provided by the National Center for Environmental Prediction and National Center for Atmospheric Research (NCEP/NCAR). We find that two of the patterns revealed from the CN extreme rainfall analysis coincide with those obtained for the pressure and temperature fields, and all four above mentioned patterns can be explained by topography, winds, and monsoon circulation. CN and ES enable to select the most informative regions for the ISM, providing realistic description of the ISM dynamics with fewer data, and also help to infer geographic pattern that are spatial signatures of the ISM. These patterns deserve a special attention for the meteorologists and can be used as markers of the ISM variability.
OPTIMIZING THROUGH CO-EVOLUTIONARY AVALANCHES
DOE Office of Scientific and Technical Information (OSTI.GOV)
S. BOETTCHER; A. PERCUS
2000-08-01
We explore a new general-purpose heuristic for finding high-quality solutions to hard optimization problems. The method, called extremal optimization, is inspired by ''self-organized critically,'' a concept introduced to describe emergent complexity in many physical systems. In contrast to Genetic Algorithms which operate on an entire ''gene-pool'' of possible solutions, extremal optimization successively replaces extremely undesirable elements of a sub-optimal solution with new, random ones. Large fluctuations, called ''avalanches,'' ensue that efficiently explore many local optima. Drawing upon models used to simulate far-from-equilibrium dynamics, extremal optimization complements approximation methods inspired by equilibrium statistical physics, such as simulated annealing. With only onemore » adjustable parameter, its performance has proved competitive with more elaborate methods, especially near phase transitions. Those phase transitions are found in the parameter space of most optimization problems, and have recently been conjectured to be the origin of some of the hardest instances in computational complexity. We will demonstrate how extremal optimization can be implemented for a variety of combinatorial optimization problems. We believe that extremal optimization will be a useful tool in the investigation of phase transitions in combinatorial optimization problems, hence valuable in elucidating the origin of computational complexity.« less
Ramiro-H, Manuel; Cruz-A, J Enrique; García-Gómez, Francisco
2017-01-01
The evaluation and quantification of scientific activity is an extremely complex task. Evaluation of research results is often difficult, and different indicators for the quantification and evaluation of scientific publications have been identified, as well as the development and success of the training programs of researchers.
n-Alcohol/Water Partition Coefficients for Decachlorobiphenyl (PCB 209)
Measurements of n-octanol/water partition coefficients (Kow) for highly hydrophobic chemicals are extremely difficult and are rarely made, in part due to the large volumes of water typically needed to quantify these compounds in the aqueous phase. An extrapolation approach using ...
The posterior auricular muscle: a useful anatomical landmark for otoplasty.
Stephen, C; Lowrie, A G
2017-05-01
The correct anatomical placement of conchomastoid sutures during suture otoplasty can sometimes prove challenging. If the suture vector is inaccurate, reduction can be difficult and this may lead to malrotation of the pinna. This paper describes the adoption of the auricularis posterior muscle, which runs from the mastoid to the concha and whose function is to adduct the pinna, as a marker for conchomastoid suture placement. The muscle is easily identified and dissected, providing a landmark for the placement of sutures onto the adjacent concha and mastoid fascia. This allows for an anatomical reduction of the pinna. It is believed that this approach will prove useful to the otoplasty surgeon.
Ron Rathfon; Keith Ruble
2007-01-01
Asian bush honeysuckles (Lonicera maackii [Rupr.] Maxim, L. morrowii Gray, and L. tartarica L.) have proved extremely invasive in eastern hardwood forests. In addition to displacing native forest ground flora and associated fauna, these understory shrubs pose a threat to forest regeneration. Effective control strategies need to be...
The life times of polymer composites in construction
NASA Astrophysics Data System (ADS)
Meier, Urs
2016-05-01
This paper discusses examples that prove the long-term reliability of Fiber Reinforced Polymers (FRP) under extreme loading conditions and outdoor weathering. Results of polymer/steel-composite anchorage systems, Glass Fiber Reinforced Polymer (GFRP) plates and shells, GFRP box girders, Carbon Fiber Reinforced Polymer (CFRP) post-tensioning tendons and CFRP stays are going to be presented.
Public Response to "The MOOC Movement" in China: Examining the Time Series of Microblogging
ERIC Educational Resources Information Center
Zhang, Jingjing; Perris, Kirk; Zheng, Qinhua; Chen, Li
2015-01-01
In China, microblogging is an extremely popular activity and is proving to be an effective mechanism to gauge perceptions about social phenomena. Between 2010 and 2015 Sina Weibo, China's largest microblogging website, generated 95,015 postings from 62,074 users referencing the term massive open online courses (MOOCs), a method of online course…
Method For Synthesizing Extremely High-Temperature Melting Materials
Saboungi, Marie-Louise; Glorieux, Benoit
2005-11-22
The invention relates to a method of synthesizing high-temperature melting materials. More specifically the invention relates to a containerless method of synthesizing very high temperature melting materials such as borides, carbides and transition-metal, lanthanide and actinide oxides, using an Aerodynamic Levitator and a laser. The object of the invention is to provide a method for synthesizing extremely high-temperature melting materials that are otherwise difficult to produce, without the use of containers, allowing the manipulation of the phase (amorphous/crystalline/metastable) and permitting changes of the environment such as different gaseous compositions.
Method for synthesizing extremely high-temperature melting materials
Saboungi, Marie-Louise; Glorieux, Benoit
2007-11-06
The invention relates to a method of synthesizing high-temperature melting materials. More specifically the invention relates to a containerless method of synthesizing very high temperature melting materials such as carbides and transition-metal, lanthanide and actinide oxides, using an aerodynamic levitator and a laser. The object of the invention is to provide a method for synthesizing extremely high-temperature melting materials that are otherwise difficult to produce, without the use of containers, allowing the manipulation of the phase (amorphous/crystalline/metastable) and permitting changes of the environment such as different gaseous compositions.
Pharmacotherapeutic approaches for treating psoriasis in difficult-to-treat areas.
Kivelevitch, Dario; Frieder, Jillian; Watson, Ian; Paek, So Yeon; Menter, M Alan
2018-04-01
Despite great therapeutic advancements in psoriasis, four notable difficult-to-treat areas including the scalp, nails, intertriginous (including genitals), and palmoplantar regions, pose a challenge to both physicians and patients. Localized disease of these specific body regions inflicts a significant burden on patients' quality of life and requires an adequate selection of treatments. Areas covered: This manuscript discusses appropriate therapies and important treatment considerations for these difficult-to-treat areas based on the available clinical data from the literature. Expert opinion: Clinical trials assessing therapies for the difficult-to-treat areas have been inadequate. With the first biological clinical trial for genital psoriasis pending publication, it is with hope that other biological agents will be evaluated for region-specific psoriasis. A greater understanding of the genetic and immunologic aspects of regional psoriasis, as well as identification of unique biomarkers, will further guide management decisions. For example, the recent discovery of the IL-36 receptor gene for generalized pustular psoriasis may prove valuable for other forms of psoriasis. Ultimately, identification of the most beneficial treatments for each psoriasis subtype and difficult-to-treat area will provide patients with maximal quality of life.
Applied extreme-value statistics
DOE Office of Scientific and Technical Information (OSTI.GOV)
Kinnison, R.R.
1983-05-01
The statistical theory of extreme values is a well established part of theoretical statistics. Unfortunately, it is seldom part of applied statistics and is infrequently a part of statistical curricula except in advanced studies programs. This has resulted in the impression that it is difficult to understand and not of practical value. In recent environmental and pollution literature, several short articles have appeared with the purpose of documenting all that is necessary for the practical application of extreme value theory to field problems (for example, Roberts, 1979). These articles are so concise that only a statistician can recognise all themore » subtleties and assumptions necessary for the correct use of the material presented. The intent of this text is to expand upon several recent articles, and to provide the necessary statistical background so that the non-statistician scientist can recognize and extreme value problem when it occurs in his work, be confident in handling simple extreme value problems himself, and know when the problem is statistically beyond his capabilities and requires consultation.« less
ERIC Educational Resources Information Center
Chan, Man Ching Esther; Clarke, David; Cao, Yiming
2018-01-01
Interactive problem solving and learning are priorities in contemporary education, but these complex processes have proved difficult to research. This project addresses the question "How do we optimise social interaction for the promotion of learning in a mathematics classroom?" Employing the logic of multi-theoretic research design,…
Glucose sensor excludes hypoglycaemia as cause of death.
Schmidt, Signe; Nørgaard, Kirsten
2012-05-01
The cause of death can be difficult to verify post-mortem in unexpected deaths in patients with Type 1 diabetes. This report describes an unexpected death in a 44-year-old man with Type 1 diabetes treated with sensor-augmented pump therapy. Continuous glucose monitoring data proved useful in determining the cause of death. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.
1990-07-01
4 The CAMPS Architecture 16 4.1 Introduction ........................................... 16 4.1.1 Using CAMPS as a Planning Tool...his interest and support during the course of this project. As we begin the development of yet another system based on the CAMPS architecture , we must...difficult planning and scheduling problems found in the real world. We hope that the CAMPS architecture will prove useful to othW.r scientists and
USDA-ARS?s Scientific Manuscript database
Ambrosia beetles Xylosandrus crassiusculus and X. germanus are among the most important exotic pests of orchards and nurseries in the US and are difficult to control using conventional insecticides because of their cryptic habits. The use of biological control agents may prove effective by targetin...
Finger jointing green southern yellow pine with a soy-based adhesive
Philip H. Steele; Roland E. Kreibicha; Petrus J. Steynberg; Richard W. Hemingway
1998-01-01
The authors present results of laboratory tests for a soy-based adhesive to bond southern yellow pine using the finger-jointing method. There was some reason to suspect that finger jointing of southern yellow pine (SYP) with the honeymoon system using soy-based adhesive might prove more difficult than for western species. The Wood Handbook classes western species in...
ERIC Educational Resources Information Center
Balcarczyk, Kelly
2014-01-01
Federal natural resource agencies are facing a human resource crisis. Many natural resource professionals are reaching retirement and attracting young adults to fill vacancies may prove difficult. Although currently on the rise from a recent fall, enrollment in natural resource degree programs has not increased overall in the past three decades,…
Recent acceleration of biomass burning and carbon losses in Alaskan forests and peatlands
Merritt R. Turetsky; Evan S. Kane; Jennifer W. Harden; Roger D. Ottmar; Kristen L. Maines; Elizabeth Hoy; Eric S. Kasischke
2010-01-01
Climate change has increased the area affected by forest fires each year in boreal North America. Increases in burned area and fire frequency are expected to stimulate boreal carbon losses. However, the impact of wildfires on carbon emissions is also affected by the severity of burning. How climate change influences the severity of biomass burning has proved difficult...
Four Studies on Aspects of Assessing Computational Performance. Technical Report No. 297.
ERIC Educational Resources Information Center
Romberg, Thomas A., Ed.
The four studies reported in this document deal with aspects of assessing students' performance on computational skills. The first study grew out of a need for an instrument to measure students' speed at recalling addition facts. This had seemed to be a very easy task, but it proved to be much more difficult than anticipated. The second study grew…
ERIC Educational Resources Information Center
Gray, Lauren; Lamanette, Michelle; Silva, Alberto; Budden, Michael C.
2009-01-01
Since the early months of 2009, the undeniable woes of the economy are being felt by many. With a record number of corporate closings, rising unemployment and the crises in the financial markets, this may prove to be a difficult year for many. This paper uses empirical evidence collected from Southeastern Louisiana University students to learn how…
The Complexity of Human Rights in Global Times: The Case of the Right to Education in South Africa
ERIC Educational Resources Information Center
Christie, Pam
2010-01-01
The right to education has an established legacy in international agreements and debates, but has nonetheless proved difficult to achieve across the countries of the world. This paper explores why this might be so. It begins by locating the current architecture of rights in Enlightenment philosophy and the political and legal formations of…
The Ability of Grade 5 Students To Use Radarsat Satellite Images.
ERIC Educational Resources Information Center
Kirman, Joseph M.; Busby, Stephanie
2000-01-01
A study examined the ability of 32 grade-5 students in Alberta (Canada) to interpret Radarsat satellite radar images. The students were able to interpret most elements of the images, but working directly with the CD-ROM proved too difficult for them. The Radarsat images have limited value as a geographic resource at the grade-5 level. (TD)
An extraordinary directive radiation based on optical antimatter at near infrared.
Mocella, Vito; Dardano, Principia; Rendina, Ivo; Cabrini, Stefano
2010-11-22
In this paper we discuss and experimentally demonstrate that in a quasi- zero-average-refractive-index (QZAI) metamaterial, in correspondence of a divergent source in near infrared (λ = 1.55 μm) the light scattered out is extremely directive (Δθ(out) = 0.06°), coupling with diffraction order of the alternating complementary media grating. With a high degree of accuracy the measurements prove also the excellent vertical confinement of the beam even in the air region of the metamaterial, in absence of any simple vertical confinement mechanism. This extremely sensitive device works on a large contact area and open news perspective to integrated spectroscopy.
STEAM INJECTION REMEDIATION IN FRACTURED BEDROCK AT LORING AIR FORCE BASE
Contaminated groundwater occurs at many Superfund, RCRA, and Brownfields sites. Chlorinated solvents which can form a dense nonaqueous phase (DNAPL) when released to the subsurface can pose an extreme challenge for remediation, as DNAPLs are often difficult to locate and even ha...
Defining Adequacy: Implications for School Business Officials.
ERIC Educational Resources Information Center
Picus, Lawrence O.
1999-01-01
Whereas equity generally focuses on relative levels or distributions of funds, adequacy stresses providing sufficient and absolute funding levels to produce desired student outcomes. Adequacy underlies many recent court decisions. Estimating costs of an adequate education is extremely difficult. School business officials must develop better…
Identification of source-sink dynamics in mountain lions of the Great Basin
USDA-ARS?s Scientific Manuscript database
Understanding population boundaries and movement rates in the field for species that are cryptic and occur at low densities is often extremely difficult and logistically prohibitive; however genetic techniques may offer insights that have previously been unattainable. We analyzed thirteen microsatel...
Field Scale Monitoring and Modeling of Water and Chemical Transfer in the Vadose Zone
USDA-ARS?s Scientific Manuscript database
Natural resource systems involve highly complex interactions of soil-plant-atmosphere-management components that are extremely difficult to quantitatively describe. Computer simulations for prediction and management of watersheds, water supply areas, and agricultural fields and farms have become inc...
2018-04-02
NASA's Solar Dynamics Observatory ran together three sequences of the sun taken in three different extreme ultraviolet wavelengths to better illustrate how different features that appear in one sequence are difficult if not impossible to see in the others (Mar. 20-21, 2018). In the red sequence (304 Angstroms), we can see very small spicules and some small prominences at the sun's edge, which are not easy to see in the other two sequences. In the second clip (193 Angstroms), we can readily observe the large and dark coronal hole, though it is difficult to make out in the others. In the third clip (171 wavelengths), we can see strands of plasma waving above the surface, especially above the one small, but bright, active region near the right edge. And these are just three of the 10 extreme ultraviolet wavelengths in which SDO images the sun every 12 seconds every day. That's a lot of data and a lot of science. Movies are available at https://photojournal.jpl.nasa.gov/catalog/PIA22360
Magadi tilapia ecological specialization: filling the early gap in the speciation continuum.
Pinho, Catarina; Faria, Rui
2016-04-01
Cichlid fish are well known for their high speciation rates, which are usually accompanied by spectacular and rapid diversification in eco-morphological and secondary sexual traits. This is best illustrated by the famous repeated explosive radiations in the African Great Lakes Tanganyika, Malawi and Victoria, each lake harbouring several hundreds of mostly endemic species. Correspondingly, cichlids diversified very rapidly in many other lakes across their range. Although the larger radiations, unparalleled in vertebrates, are certainly the most intriguing, they are also the most intricate and difficult to address because of their complex nature. This is where smaller, simpler systems may prove to be the most useful. In this issue of Molecular Ecology, Kavembe et al. (2016) report very recent genetic diversification accompanied by ecological specialization in cichlids of the small and ecologically extreme Lake Magadi, in Kenya. Combining geometric morphometrics, stable isotope analysis, population genomics using RADSeq data and coalescent-based modelling techniques, the authors characterize the eco-morphological differences between genetically distinct populations of Magadi tilapia (Alcolapia grahami), which are consistent with the different environmental conditions they experience, and infer their history of divergence. The simplicity of the focal system and the use of a multidisciplinary approach make this work particularly important for our understanding of the early stages of speciation, in both cichlids and other organisms. © 2016 John Wiley & Sons Ltd.
Expedited Selection of NMR Chiral Solvating Agents for Determination of Enantiopurity
2016-01-01
The use of NMR chiral solvating agents (CSAs) for the analysis of enantiopurity has been known for decades, but has been supplanted in recent years by chromatographic enantioseparation technology. While chromatographic methods for the analysis of enantiopurity are now commonplace and easy to implement, there are still individual compounds and entire classes of analytes where enantioseparation can prove extremely difficult, notably, compounds that are chiral by virtue of very subtle differences such as isotopic substitution or small differences in alkyl chain length. NMR analysis using CSAs can often be useful for such problems, but the traditional approach to selection of an appropriate CSA and the development of an NMR-based analysis method often involves a trial-and-error approach that can be relatively slow and tedious. In this study we describe a high-throughput experimentation approach to the selection of NMR CSAs that employs automation-enabled screening of prepared libraries of CSAs in a systematic fashion. This approach affords excellent results for a standard set of enantioenriched compounds, providing a valuable comparative data set for the effectiveness of CSAs for different classes of compounds. In addition, the technique has been successfully applied to challenging pharmaceutical development problems that are not amenable to chromatographic solutions. Overall, this methodology provides a rapid and powerful approach for investigating enantiopurity that compliments and augments conventional chromatographic approaches. PMID:27280168
Sources and properties of non-exhaust particulate matter from road traffic: a review.
Thorpe, Alistair; Harrison, Roy M
2008-08-01
While emissions control regulation has led to a substantial reduction in exhaust emissions from road traffic, currently non-exhaust emissions from road vehicles are unabated. These include particles from brake wear, tyre wear, road surface abrasion and resuspension in the wake of passing traffic. Quantification of the magnitude of such emissions is problematic both in the laboratory and the field and the latter depends heavily upon a knowledge of the physical and chemical properties of non-exhaust particles. This review looks at each source in turn, reviewing the available information on the source materials and particles derived from them in laboratory studies. In a final section, some of the key publications dealing with measurements in road tunnels and the roadside environment are reviewed. It is concluded that with the exception of brake dust particles which may be identified from their copper (Cu) and antimony (Sb) content, unequivocal identification of particles from other sources is likely to prove extremely difficult, either because of the lack of suitable tracer elements or compounds, or because of the interactions between sources prior to the emission process. Even in the case of brake dust, problems will arise in distinguishing directly emitted particles from those arising from resuspension of deposited brake dust from the road surface, or that derived from entrainment of polluted roadside soils, either directly or as a component of road surface dust.
NASA Astrophysics Data System (ADS)
Lindegren, Lennart
2012-01-01
The launch of the Hipparcos satellite in 1989 and the Hubble Space Telescope in 1990 revolutionized astrometry. By no means does this imply that not much progress was made in the ground-based techniques used exclusively until then. On the contrary, the 1960s to 1980s saw an intense development of new or highly improved instruments, including photoelectric meridian circles, automated plate measuring machines, and the use of chargecoupled device (CCD) detectors for small-field differential astrometry (for a review of optical astrometry at the time, see Monet 1988). In the radio domain, very long baseline interferometry (VLBI) astrometry already provided an extragalactic reference frame accurate to about 1 milliarcsecond (mas) (Ma et al. 1990). Spectacular improvements were made in terms of accuracy, the faintness of the observed objects, and their numbers. However, there was a widening gulf between small-angle astrometry, where differential techniques could overcome atmospheric effects down to below 1 mas, and large-angle astrometry, where conventional instruments such as meridian circles seemed to have hit a barrier in the underlying systematic errors at about 100 mas. Though very precise, the small-angle measurements were of limited use for the determination of positions and proper motions, due to the lack of suitable reference objects in the small fields, and even for parallaxes the necessary correction for the mean parallax of background stars was highly non-trivial. Linking the optical observations to the accurate VLBI frame also proved extremely difficult.
NASA Astrophysics Data System (ADS)
Trew, Noel; Linn, Aaron; Nelson, Zac; Burnett, Greg; Sedillo, Mike
2012-06-01
Today, warfighters are burdened by a web of cables linking technologies that span the head and torso regions of the body. These cables help to provide interoperability between helmet-worn peripherals such as head mounted displays (HMDs), cameras, and communication equipment with chest-worn computers and radios. Although promoting enhanced capabilities, this cabling also poses snag hazards and makes it difficult for the warfighter to extricate himself from his kit when necessary. A newly developed wireless personal area network (WPAN), one that uses optical transceivers, may prove to be an acceptable alternative to traditional cabling. Researchers at the Air Force Research Laboratory's 711th Human Performance Wing are exploring how best to mount the WPAN transceivers to the body in order to facilitate unimpeded data transfer while also maintaining the operator's natural range of motion. This report describes the two-step research process used to identify the performance limitations and usability of a body-worn optical wireless system. Firstly, researchers characterized the field of view for the current generation of optical WPAN transceivers. Then, this field of view was compared with anthropometric data describing the range of motion of the cervical vertebrae to see if the data link would be lost at the extremes of an operator's head movement. Finally, this report includes an additional discussion of other possible military applications for an optical WPAN.
AFM-based tribological study of nanopatterned surfaces: the influence of contact area instabilities.
Rota, A; Serpini, E; Gazzadi, G C; Valeri, S
2016-04-06
Although the importance of morphology on the tribological properties of surfaces has long been proved, an exhaustive understanding of nanopatterning effects is still lacking due to the difficulty in both fabricating 'really nano-' structures and detecting their tribological properties. In the present work we show how the probe-surface contact area can be a critical parameter due to its remarkable local variability, making a correct interpretation of the data very difficult in the case of extremely small nanofeatures. Regular arrays of parallel 1D straight nanoprotrusions were fabricated by means of a low-dose focused ion beam, taking advantage of the amorphization-related swelling effect. The tribological properties of the patterns were detected in the presence of air and in vacuum (dry ambient) by atomic force microscopy. We have introduced a novel procedure and data analysis to reduce the uncertainties related to contact instabilities. The real time estimation of the radius of curvature of the contacting asperity enables us to study the dependence of the tribological properties of the patterns from their geometrical characteristics. The effect of the patterns on both adhesion and the coefficient of friction strongly depends on the contact area, which is linked to the local radius of curvature of the probe. However, a detectable hydrophobic character induced on the hydrophilic native SiO2 has been observed as well. The results suggest a scenario for capillary formation on the patterns.
Multi-layered foil capture of micrometeoroids and orbital debris in low Earth orbit
NASA Astrophysics Data System (ADS)
Kearsley, A.; Graham, G.
Much of our knowledge concerning the sub-millimetre orbital debris population that poses a threat to orbiting satellites has been gleaned from examination of surfaces retrieved and subsequently analysed as part of post-flight investigations. The preservation of the hypervelocity impact-derived remnants located on these surfaces is very variable, whether of space debris or micrometeoroid origin. Whilst glass and metallic materials show highly visible impact craters when examined using optical and electron microscopes, complex mixing between the target material and the impacting particle may make unambiguous interpretation of the impactor origin difficult or impossible. Our recent detailed examination of selected multi-layered insulation (MLI) foils from the ISAS Space Flyer Unit (SFU), and our preliminary study of NASA's Trek blanket, exposed on the Mir station, show that these constructions have the potential to preserve abundant residue material of a quality sufficient for detailed analysis. Although there are still limitations on the recognition of certain sources of orbital debris, the foils complement the metal and glass substrates. We suggest that a purpose-built multi-layered foil structure may prove to be extremely effective for rapid collection and unambiguous analysis of impact- derived residues. Such a collector could be used an environmental monitor for ISS, as it would have low mass, high durability, easy deployment, recovery and storage, making it an economically viable and attractive option.
Laser Scanning System for Pressure and Temperature Paints
NASA Technical Reports Server (NTRS)
Sullivan, John
1997-01-01
Acquiring pressure maps of aerodynamic surfaces is very important for improving and validating the performance of aerospace vehicles. Traditional pressure measurements are taken with pressure taps embedded in the model surface that are connected to transducers. While pressure taps allow highly accurate measurements to be acquired, they do have several drawbacks. Pressure taps do not give good spatial resolution due to the need for individual pressure tubes, compounded by limited space available inside models. Also, building a model proves very costly if taps are needed because of the large amount of labor necessary to drill, connect and test each one. The typical cost to install one tap is about $200. Recently, a new method for measuring pressure on aerodynamic surfaces has been developed utilizing a technology known as pressure sensitive paints (PSP). Using PSP, pressure distributions can be acquired optically with high spatial resolution and simple model preparation. Flow structures can be easily visualized using PSP, but are missed using low spatial resolution arrays of pressure taps. PSP even allows pressure distributions to be found on rotating machinery where previously this has been extremely difficult or even impossible. The goal of this research is to develop a laser scanning system for use with pressure sensitive paints that allows accurate pressure measurements to be obtained on various aerodynamic surfaces ranging from wind tunnel models to high speed jet engine compressor blades.
IL-6 blockade in the management of non-infectious uveitis.
Lopalco, Giuseppe; Fabiani, Claudia; Sota, Jurgen; Lucherini, Orso Maria; Tosi, Gian Marco; Frediani, Bruno; Iannone, Florenzo; Galeazzi, Mauro; Franceschini, Rossella; Rigante, Donato; Cantarini, Luca
2017-07-01
Several pathogenetic studies have paved the way for a newer more rational therapeutic approach to non-infectious uveitis, and treatment of different forms of immune-driven uveitis has drastically evolved in recent years after the advent of biotechnological drugs. Tumor necrosis factor-α targeted therapies, the first-line recommended biologics in uveitis, have certainly led to remarkable results in patients with non-infectious uveitis. Nevertheless, the decision-making process turns out to be extremely difficult in anti-tumor necrosis factor or multidrug-resistant cases. Interleukin (IL)-6 holds a critical role in the pathogenic pathways of uveitis, due to its extended and protean range of effects. On this background, manipulation of IL-6 inflammatory cascade has unraveled encouraging outcomes. For instance, rising evidence has been achieved regarding the successful use of tocilizumab, the humanized monoclonal antibody targeted against the IL-6 receptor, in treating uveitis related to juvenile idiopathic arthritis or Behçet's disease. Similar findings have also been reported for uveitis associated with systemic disorders, such as rheumatoid arthritis or multicentric Castleman disease, but also for idiopathic uveitis, the rare birdshot chorioretinopathy, and even in cases complicated by macular edema. This work provides a digest of all current experiences and evidences concerning IL-6 blockade, as suggested by the medical literature, proving its potential role in the management of non-infectious uveitis.
Evaluating HDR photos using Web 2.0 technology
NASA Astrophysics Data System (ADS)
Qiu, Guoping; Mei, Yujie; Duan, Jiang
2011-01-01
High dynamic range (HDR) photography is an emerging technology that has the potential to dramatically enhance the visual quality and realism of digital photos. One of the key technical challenges of HDR photography is displaying HDR photos on conventional devices through tone mapping or dynamic range compression. Although many different tone mapping techniques have been developed in recent years, evaluating tone mapping operators prove to be extremely difficult. Web2.0, social media and crowd-sourcing are emerging Internet technologies which can be harnessed to harvest the brain power of the mass to solve difficult problems in science, engineering and businesses. Paired comparison is used in the scientific study of preferences and attitudes and has been shown to be capable of obtaining an interval-scale ordering of items along a psychometric dimension such as preference or importance. In this paper, we exploit these technologies for evaluating HDR tone mapping algorithms. We have developed a Web2.0 style system that enables Internet users from anywhere to evaluate tone mapped HDR photos at any time. We adopt a simple paired comparison protocol, Internet users are presented a pair of tone mapped images and are simply asked to select the one that they think is better or click a "no difference" button. These user inputs are collected in the web server and analyzed by a rank aggregation algorithm which ranks the tone mapped photos according to the votes they received. We present experimental results which demonstrate that the emerging Internet technologies can be exploited as a new paradigm for evaluating HDR tone mapping algorithms. The advantages of this approach include the potential of collecting large user inputs under a variety of viewing environments rather than limited user participation under controlled laboratory environments thus enabling more robust and reliable quality assessment. We also present data analysis to correlate user generated qualitative indices with quantitative image statistics which may provide useful guidance for developing better tone mapping operators.
The Analytic Hierarchy Process and Participatory Decisionmaking
Daniel L. Schmoldt; Daniel L. Peterson; Robert L. Smith
1995-01-01
Managing natural resource lands requires social, as well as biophysical, considerations. Unfortunately, it is extremely difficult to accurately assess and quantify changing social preferences, and to aggregate conflicting opinions held by diverse social groups. The Analytic Hierarchy Process (AHP) provides a systematic, explicit, rigorous, and robust mechanism for...
USDA-ARS?s Scientific Manuscript database
Gardner saltbush ecosystems are increasingly being invaded by halogeton (Halogeton glomeratus), which is extremely competitive and believed to increase soil surface salinity making it difficult to establish other desired plants. This study evaluated the ability of forage kochia (Kochia prostrata), ...
ERIC Educational Resources Information Center
Van Der Werf, Martin
2007-01-01
As the number of American students studying overseas increases, it will be difficult for colleges to establish or find enough adequate programs with challenging curricula. Students desire ever more remote locations, and colleges are being pushed to support the extremely adventurous. With more students studying abroad, and amid heightened fears…
"Vulnerable Families": Reflections on a Difficult Category
ERIC Educational Resources Information Center
Bauer, Petra; Wiezorek, Christine
2016-01-01
The term "vulnerable families" refers to familial living situations that are considered problematic, with a particular need for socially responsible, professionally provided support. This means of categorising families is extremely ambivalent, indicating not only a need for society to support forms of family life and family achievements,…
The extremely high exposure levels evaluated in prior investigations relating elevated levels of drinking water arsenic and hypertension prevalence make extrapolation to potential vascular effects at lower exposure levels very difficult. A cross-sectional study was conducted on ...
Measurements of n-octanol/water partition coefficients (KOW) for highly hydrophobic chemicals, i.e., greater than 108, are extremely difficult and are rarely made, in part because the vanishingly small concentrations in the water phase require extraordinary analytical sensitivity...
Sex Work Research: Methodological and Ethical Challenges
ERIC Educational Resources Information Center
Shaver, Frances M.
2005-01-01
The challenges involved in the design of ethical, nonexploitative research projects with sex workers or any other marginalized population are significant. First, the size and boundaries of the population are unknown, making it extremely difficult to get a representative sample. Second, because membership in hidden populations often involves…
Development of Semiochemical Based Control Programs for Arthropod Pests of Honeybees
USDA-ARS?s Scientific Manuscript database
In recent years the apiculture industry has experienced serious problems from serious invasions by exotic pests including Varroa destructor and the Small hive beetle, Aethina tumida. Control of these pests is difficult and problematic because Honey bees are extremely sensitive to pesticides and the...
Multifield Galileons and higher codimension branes
Hinterbichler, Kurt; Trodden, Mark; Wesley, Daniel
2010-12-07
We studied a multi-field generalizations of the galileon - a popular idea of how to modify gravity to account for the acceleration of the universe. We derived an extremely restrictive theory of multiple galileon fields, and explored some properties of this theory, including proving a general non-renormalization theorem: multi-field galileons are not renormalized quantum mechanically to any loop in perturbation theory.
Deformations of the gyroid and Lidinoid minimal surfaces using flat structures
NASA Astrophysics Data System (ADS)
Weyhaupt, Adam
2015-03-01
Mathematically, the challenge in proving the existence of a purported triply periodic minimal surface is in computing parameter values that depend on a system of equations defined by elliptic integrals. This is generally very difficult. In the presence of some symmetry, however, a technique developed by Weber and Wolf can reduce these elliptic integrals to basic algebra and geometry of polygons. These techniques can easily prove the existence of some surfaces and the presence of a family of solutions. Families of surfaces are important mathematically, but recent work by Seddon, et. al., experimentally confirms that these families of surfaces can occur physically as well. In this talk, we give a brief overview of the technique and show how it can be applied to prove the existence of several families of surfaces, including lower symmetry variants of the gyroid and Lidinoid such as the rG, rPD, tG, and rL. We also conjecture a map of the moduli space of triply periodic minimal surfaces of genus 3.
ERIC Educational Resources Information Center
Thompson, Carol; Wolstencroft, Peter
2018-01-01
The role of the middle manager has proved to be a difficult one to define due to the fluid nature of the tasks performed and the heterogeneity of understanding that exists for the term. This is further complicated by the differences associated with the context in which individual manager's work. This research, which explores the drive towards…
Christopher B. Dow; Brandon M. Collins; Scott L. Stephens
2016-01-01
Finding novel ways to plan and implement landscape-level forest treatments that protect sensitive wildlife and other key ecosystem components, while also reducing the risk of large-scale, high-severity fires, can prove to be difficult. We examined alternative approaches to landscape-scale fuel-treatment design for the same landscape. These approaches included two...
Michael J. Dockry
2015-01-01
Many research institutions and professional societies are looking to enhance the diversity of their members, employees, and scientists. To do this, their efforts often focus on recruitment and retention of minority employees and employees from protected classes (e.g., race, religion, sex, age); however, recruitment and retention efforts can prove difficult and do not...
DOE Office of Scientific and Technical Information (OSTI.GOV)
Nuckols, T.E.
Environmental monitoring is a very important activity performed on landfills. The data obtained is vital to ensuring that the landfill is in compliance with the regulatory standards. More importantly monitoring data can be used as historical documentation should enforcement or legal action be taken against the landfill. It is very difficult, if not impossible, to defend against alleged mismanagement or misconduct when there is no record to prove otherwise.
USDA-ARS?s Scientific Manuscript database
The cattle tick, Rhipicephalus (Boophilus) microplus, has a genome over 2.4 times the size of the human genome, and with over 70% of repetitive DNA, this genome would prove very costly to sequence at today's prices and difficult to assemble and analyze. BAC clones give insight into the genome struct...
ERIC Educational Resources Information Center
Rantala, Jukka; Manninen, Marika; van den Berg, Marko
2016-01-01
In 2011, the Finnish National Board of Education assessed the learning outcomes of history with a study whose results raised doubts about the fulfilment of the goals of history education. This article seeks to expand awareness about Finnish adolescents' understanding of historical empathy. The study assessed twenty-two 16-17-year-old high school…
ERIC Educational Resources Information Center
Brown, Chris; Zhang, Dell
2017-01-01
While beneficial, the consistent and regular use of evidence to improve teaching and learning is proving difficult to achieve in practice. This paper attempts to shed new light on this issue by examining the question: "If using evidence to inform teaching practice is rational behaviour, why aren't all teachers engaged in it?" It first…
"Teaching Physics as One of the Humanities": The History of (Harvard) Project Physics, 1961-1970
ERIC Educational Resources Information Center
Meshoulam, David
2014-01-01
In the United States after World War II, science had come to occupy a central place in the minds of policy makers, scientists, and the public. Negotiating different views between these groups proved a difficult task and spilled into debates over the role and scope of science education. To examine this process, this dissertation traces the history…
Russia’s Approach to Cyber Warfare
2016-09-01
mobilized. However, the crowd-sourced approach that has typified how the Kremlin has utilized hackers and criminal networks in the past is likely to be...specially trained and equipped troops. According to one source, these troops would include hackers , journalists, specialists in strategic...direct links to the Russian government are difficult to prove conclusively (and the Russian government denies that it sponsors any hacker groups
Regioselective Synthesis of Cellulose Ester Homopolymers
Daiqiang Xu; Kristen Voiges; Thomas Elder; Petra Mischnick; Kevin J. Edgar
2012-01-01
Regioselective synthesis of cellulose esters is extremely difficult due to the small reactivity differences between cellulose hydroxyl groups, small differences in steric demand between acyl moieties of interest, and the difficulty of attaching and detaching many protecting groups in the presence of cellulose ester moieties without removing the ester groups. Yet the...
Phosphorus (P) remediation is an extremely difficult and costly environmental problem and could cost $44.5 billion for treatment using conventional water treatment plants to meet EPA requirements. Phosphorus runoffs can lead to dead zones due to eutrophication and also ca...
Working with Child Prostitutes in Thailand: Problems of Practice and Interpretation
ERIC Educational Resources Information Center
Montgomery, Heather
2007-01-01
Conducting anthropological fieldwork on the emotive issue of child prostitution raises difficult issues for anthropologists and other researchers. This article examines the ethical dilemmas of working with these extremely vulnerable children, focusing on the difference between the researcher's own interpretations and those given by the children…
Guidelines to Support Professional Copyright Practice
ERIC Educational Resources Information Center
Dryden, Jean
2012-01-01
Copyright is extremely complex, and it is difficult to convey its complexities in a clear and concise form. Through decades of experience, archivists developed informal best practices for dealing with copyright in the analog world; however the application of copyright in the digital environment is evolving in response to rapidly changing…
Educational Management within a Young Offender Institution.
ERIC Educational Resources Information Center
Fryer, Winny; Fryer, Paul
1992-01-01
Examines educational theory and objectives within prisons and relates these to the real-time case study of the Young Offender Institution at Whatton, in Nottinghamshire, England. Measuring success and cost effectiveness is extremely difficult in the prison education field, and a significant gap exists between the theoretical model and everyday…
Accountability: Its Implications for Provincial and State Governments.
ERIC Educational Resources Information Center
Kolesar, H.
This paper examines the implications of the accountability concept for provincial or State authorities. Accountability is defined as a concomitant of an agreement between two parties. The author suggests that, in education, agreements between parties have lacked preciseness and clarity, making it extremely difficult to assess performance and to…
The American Indian: A Very Private People.
ERIC Educational Resources Information Center
Chan, Carole; Hamby, John
American Indian urban immigration has put between 33% and 50% of all Indians in urban settings where they invariably are subjected to an initial cultural shock. Leaving the reservation to improve their socioeconomic status, Indians find urban adjustment extremely difficult. The Anglo culture is inherently opposed to the "Indian Way", for it…
Creating 3D Physical Models to Probe Student Understanding of Macromolecular Structure
ERIC Educational Resources Information Center
Cooper, A. Kat; Oliver-Hoyo, M. T.
2017-01-01
The high degree of complexity of macromolecular structure is extremely difficult for students to process. Students struggle to translate the simplified two-dimensional representations commonly used in biochemistry instruction to three-dimensional aspects crucial in understanding structure-property relationships. We designed four different physical…
A Zone for Deliberation? Methodological Challenges in Fields of Political Unrest
ERIC Educational Resources Information Center
Westrheim, Kariane; Lillejord, Solvi
2007-01-01
This article outlines certain problems and challenges facing the qualitative researcher who enters fields that are either extremely difficult to access or potentially hostile towards outsiders. Problems and dilemmas in such contexts are highlighted by reference to fieldwork research among PKK (Kurdistan Worker's Party) guerrillas in North…
DOT National Transportation Integrated Search
1973-01-01
It was found that valid predictions of the use of containers were extremely difficult to make because of the lack of reliable data. Further, during the time of the study, the local ports negotiated for international consolidation, the dollar was deva...
From Positive Reinforcement to Positive Behaviors: An Everyday Guide for the Practitioner
ERIC Educational Resources Information Center
Sigler, Ellen A.; Aamidor, Shirley
2005-01-01
There are various opinions concerning the value of positive reinforcement when discussing modifying behaviors of young children. In some cases, individuals considered positive reinforcement difficult to implement and, in extreme cases, even felt it to be detrimental. Educators often use praise interchangeably with positive reinforcement when…
U.S. National Security Policy. Revision.
1986-03-01
World War II, Sino-American relations have fluctuated from tacit war (in the early 1950s) to a quasi alliance (in the late 1970s). This .I historical ... volatility makes prediction of the long-term future extremely difficult, but the character of Chinese foreign policy in 2010 well may be (after the
Changing University Students' Alternative Conceptions of Optics by Active Learning
ERIC Educational Resources Information Center
Hadžibegovic, Zalkida; Sliško, Josip
2013-01-01
Active learning is individual and group participation in effective activities such as in-class observing, writing, experimenting, discussion, solving problems, and talking about to-be-learned topics. Some instructors believe that active learning is impossible, or at least extremely difficult to achieve in large lecture sessions. Nevertheless, the…
Improving Professional Judgments of Risk and Amenability in Juvenile Justice
ERIC Educational Resources Information Center
Mulvey, Edward P.; Iselin, Anne-Marie R.
2008-01-01
The dual requirement to ensure community safety and promote a youthful offender's positive development permeates policy and frames daily practice in juvenile justice. Balancing those two demands, explain Edward Mulvey and Anne-Marie Iselin, requires justice system professionals at all levels to make extremely difficult decisions about the likely…
EVALUATING CUMULATIVE EFFECTS OF DISTURBANCE ON THE HYDROLOGIC FUNCTION OF BOGS, FENS, AND MIRES
Few quantitative studies have been done on the hydrology of fens, bogs and mires, and consequently any predictions of the cumulative impacts of disturbances on their hydrologic functions is extremely difficult. or example, few data are available on the role of bogs and fens with ...
ERIC Educational Resources Information Center
Williams, Kathryn R.
2007-01-01
The safety and health hazards related to recycling of used rubber, due to the scarcity and high price of virgin rubber are reported. Various threats like stagnant water pools trapped in tires leading to diseases and ignited tires, which become very difficult to extinguish and generating smoke that is extremely detrimental to the environment, have…
Sowing pregerminated northern red oak acorns
Richard M. Godman; Gilbert A. Mattson
1992-01-01
Northern red oak is extremely difficult to regenerate, although it has produced good acorn crops nearly half of the last 32 years in northern Wisconsin. Field trials have shown that for successful seeding, you must protect acorns from predation by wildlife and sow them when temperatures are most favorable for germination.
Estimating timber supply from private forests
D.F. Dennis
1991-01-01
Nonindustrial private landowners, who hold a majority of the Nation's commercial forests, own land primarily for reasons other than timber production. The multiple objective and dynamic nature of private ownership make planning and estimation of timber availability from this sector extremely difficult. Insight into the determinants of timber supply from private...
Challenges Facing Guitar Education
ERIC Educational Resources Information Center
Harrison, Eli
2010-01-01
The guitar is an extremely versatile instrument. It can produce complex chords and arpeggiated textures as readily as single-note melodies. In the twentieth century alone, it has appeared in a wide range of genres; classical, jazz, blues, rock, and bossa nova compose a partial list. The guitar is also a difficult instrument. Inconsistencies across…
Education: Perceiving the Disease and Prescribing the Remedy
ERIC Educational Resources Information Center
Clarken, Rodney H.
2007-01-01
Modern thinkers chiefly identify development with materialistic and economic factors. Education is often measured and evaluated by the same standard: its material and economic impact on the individual and society. A moral balance is recommended to this excessively materialistic perspective. It is extremely difficult to unravel the complexities of…
Employment Problems of the Vietnam Veteran. Special Report.
ERIC Educational Resources Information Center
National Advisory Council on Vocational Education, Washington, DC.
Vietnam veterans are finding it extremely difficult of find jobs upon their return home. Altogether there are approximately 320,000 known unemployed veterans. Statistics show that they have a higher unemployment rate than nonveterans, and that the unemployment persists longer. Factors contributing to this condition are the economic slump, a…
NASA Astrophysics Data System (ADS)
da Costa, Diogo Ricardo; Hansen, Matheus; Guarise, Gustavo; Medrano-T, Rene O.; Leonel, Edson D.
2016-04-01
We show that extreme orbits, trajectories that connect local maximum and minimum values of one dimensional maps, play a major role in the parameter space of dissipative systems dictating the organization for the windows of periodicity, hence producing sets of shrimp-like structures. Here we solve three fundamental problems regarding the distribution of these sets and give: (i) their precise localization in the parameter space, even for sets of very high periods; (ii) their local and global distributions along cascades; and (iii) the association of these cascades to complicate sets of periodicity. The extreme orbits are proved to be a powerful indicator to investigate the organization of windows of periodicity in parameter planes. As applications of the theory, we obtain some results for the circle map and perturbed logistic map. The formalism presented here can be extended to many other different nonlinear and dissipative systems.
G-Equivalent Acceleration Tolerance in the Eutardigrade Species Hypsibius dujardini.
Vasanthan, Tarushika; Alejaldre, Lorea; Hider, Jessica; Patel, Shreya; Husain, Nabiha; Umapathisivam, Bavithra; Stone, Jonathon
2017-01-01
Tardigrades are microscopic organisms renowned for their ability to survive extreme environmental conditions. Tardigrade extreme-tolerance research has centered on the ability to withstand desiccation, low and high temperatures, and high hydrostatic pressure and radiation levels. Tardigrade tolerance to hypergravity, however, has yet to be described. We used the eutardigrade species Hypsibius dujardini to investigate short-term tolerance to g-equivalent accelerations (i.e., mimicking g-forces). Data obtained from specimens centrifuged between 3421g and 16,060g for 1 min inclusively reveal tolerance in an acceleration-dependent relation, with lower survivorship and egg production at higher accelerations. This is the first study to demonstrate tardigrade potential for tolerance to hypergravity and describe expected effects on tardigrade survival and reproduction. These findings will prove to be useful in lithopanspermia research (i.e., viable spread in meteoritic rocks). Key Words: Astrobiology-Extreme tolerance-Hypergravity-Tardigrade. Astrobiology 17, 55-60.
Wind Tunnel Data Fusion and Immersive Visualization: A Case Study
NASA Technical Reports Server (NTRS)
Severance, Kurt; Brewster, Paul; Lazos, Barry; Keefe, Daniel
2001-01-01
This case study describes the process of fusing the data from several wind tunnel experiments into a single coherent visualization. Each experiment was conducted independently and was designed to explore different flow features around airplane landing gear. In the past, it would have been very difficult to correlate results from the different experiments. However, with a single 3-D visualization representing the fusion of the three experiments, significant insight into the composite flowfield was observed that would have been extremely difficult to obtain by studying its component parts. The results are even more compelling when viewed in an immersive environment.
Better Redd than Dead: Optimizing Reservoir Operations for Wild Fish Survival During Drought
NASA Astrophysics Data System (ADS)
Adams, L. E.; Lund, J. R.; Quiñones, R.
2014-12-01
Extreme droughts are difficult to predict and may incur large economic and ecological costs. Dam operations in drought usually consider minimizing economic costs. However, dam operations also offer an opportunity to increase wild fish survival under difficult conditions. Here, we develop a probabilistic optimization approach to developing reservoir release schedules to maximize fish survival in regulated rivers. A case study applies the approach to wild Fall-run Chinook Salmon below Folsom Dam on California's American River. Our results indicate that releasing more water early in the drought will, on average, save more wild fish over the long term.
Combining local search with co-evolution in a remarkably simple way
DOE Office of Scientific and Technical Information (OSTI.GOV)
Boettcher, S.; Percus, A.
2000-05-01
The authors explore a new general-purpose heuristic for finding high-quality solutions to hard optimization problem. The method, called extremal optimization, is inspired by self-organized criticality, a concept introduced to describe emergent complexity in physical systems. In contrast to genetic algorithms, which operate on an entire gene-pool of possible solutions, extremal optimization successively replaces extremely undesirable elements of a single sub-optimal solution with new, random ones. Large fluctuations, or avalanches, ensue that efficiently explore many local optima. Drawing upon models used to simulate far-from-equilibrium dynamics, extremal optimization complements heuristics inspired by equilibrium statistical physics, such as simulated annealing. With only onemore » adjustable parameter, its performance has proved competitive with more elaborate methods, especially near phase transitions. Phase transitions are found in many combinatorial optimization problems, and have been conjectured to occur in the region of parameter space containing the hardest instances. We demonstrate how extremal optimization can be implemented for a variety of hard optimization problems. We believe that this will be a useful tool in the investigation of phase transitions in combinatorial optimization, thereby helping to elucidate the origin of computational complexity.« less
Ülker, Kahraman; Akyer, Şahika P; Temur, İsmail; Tan, Temel; Karaca, Mehmet; Adıgüzel, Esat; Gül, Abdülaziz
2012-02-01
Parapagus (laterally fused), diprosopus (two faces), dibrachius (two upper extremities), dipus (two lower extremities) conjoined twinning is extremely rare. The coexistence of anencephaly with a contiguous spinal defect (craniorachischisis totalis) makes the present case one of the rarest of the published cases. In our case, it was difficult to make the final diagnosis by two-dimensional abdominal and vaginal ultrasound. Three-dimensional ultrasound was helpful for final diagnosis and post-abortal examination confirmed the prenatal ultrasound diagnosis. The heart, diaphragm, liver and perineum were all united. Fine dissection of the heart showed four vessels arising from the ventricles and a membranous type ventricular septal defect. © 2011 The Authors. Journal of Obstetrics and Gynaecology Research © 2011 Japan Society of Obstetrics and Gynecology.
Extreme hydronephrosis due to uretropelvic junction obstruction in infant (case report).
Krzemień, Grażyna; Szmigielska, Agnieszka; Bombiński, Przemysław; Barczuk, Marzena; Biejat, Agnieszka; Warchoł, Stanisław; Dudek-Warchoł, Teresa
2016-01-01
Hydronephrosis is the one of the most common congenital abnormalities of urinary tract. The left kidney is more commonly affected than the right side and is more common in males. To determine the role of ultrasonography, renal dynamic scintigraphy and lowerdose computed tomography urography in preoperative diagnostic workup of infant with extreme hydronephrosis. We presented the boy with antenatally diagnosed hydronephrosis. In serial, postnatal ultrasonography, renal scintigraphy and computed tomography urography we observed slightly declining function in the dilated kidney and increasing pelvic dilatation. Pyeloplasty was performed at the age of four months with good result. Results of ultrasonography and renal dynamic scintigraphy in child with extreme hydronephrosis can be difficult to asses, therefore before the surgical procedure a lower-dose computed tomography urography should be performed.
Dismounted Complex Blast Injury.
Andersen, Romney C; Fleming, Mark; Forsberg, Jonathan A; Gordon, Wade T; Nanos, George P; Charlton, Michael T; Ficke, James R
2012-01-01
The severe Dismounted Complex Blast Injury (DCBI) is characterized by high-energy injuries to the bilateral lower extremities (usually proximal transfemoral amputations) and/or upper extremity (usually involving the non-dominant side), in addition to open pelvic injuries, genitourinary, and abdominal trauma. Initial resuscitation and multidisciplinary surgical management appear to be the keys to survival. Definitive treatment follows general principals of open wound management and includes decontamination through aggressive and frequent debridement, hemorrhage control, viable tissue preservation, and appropriate timing of wound closure. These devastating injuries are associated with paradoxically favorable survival rates, but associated injuries and higher amputation levels lead to more difficult reconstructive challenges.
Phase transitions and dynamics of bulk and interfacial water.
Franzese, G; Hernando-Martínez, A; Kumar, P; Mazza, M G; Stokely, K; Strekalova, E G; de los Santos, F; Stanley, H E
2010-07-21
New experiments on water at the surface of proteins at very low temperature display intriguing dynamic behaviors. The extreme conditions of these experiments make it difficult to explore the wide range of thermodynamic state points needed to offer a suitable interpretation. Detailed simulations suffer from the same problem, where equilibration times at low temperature become extremely long. We show how Monte Carlo simulations and mean field calculations using a tractable model of water help interpret the experimental results. Here we summarize the results for bulk water and investigate the thermodynamic and dynamic properties of supercooled water at an interface.
Diagnostic studies of ensemble forecast "jumps"
NASA Astrophysics Data System (ADS)
Magnusson, Linus; Hewson, Tim; Ferranti, Laura; Rodwell, Mark
2016-04-01
During 2015 we saw exceptional consistency in successive seasonal forecasts produced at ECMWF, for the winter period 2015/16, right across the globe. This winter was characterised by a well-predicted and unusually strong El Nino, and some have ascribed the consistency to that. For most of December this consistency was mirrored in the (separate) ECMWF monthly forecast system, which correctly predicted anomalously strong (mild) zonal flow, over the North Atlantic and western Eurasia, even in forecasts for weeks 3 and 4. In monthly forecasts in general these weeks are often devoid of strong signals. However in late December and early January strong signals, even in week 2, proved to be incorrect, most notably over the North Atlantic and Eurasian sectors. Indeed on at least two occasions the outcome was beyond the ensemble forecast range over Scandinavia. In one of these conditions flipped from extreme mild to extreme cold as a high latitude block developed. Temperature prediction is very important to many customers, notably those dealing with renewable energy, because cold weather causes increased demand but also tends to coincide with reduced wind power production. So understandably jumps can cause consternation amongst some customer groups, and are very difficult to handle operationally. This presentation will discuss the results of initial diagnostic investigations into what caused the "ensemble jumps", particularly at the week two lead, though reference will also be made to a related shorter range (day 3) jump that was important for flooding over the UK. Initial results suggest that an inability of the ECMWF model to correctly represent convective outbreaks over North America (that for winter-time were quite extreme) played an important role. Significantly, during this period, an unusually large amount of upper air data over North America was rejected or ascribed low weight. These results bear similarities to previous diagnostic studies at ECMWF, wherein major convective outbreaks in spring and early summer over North America were shown to have a detrimental impact on forecast quality. The possible contributions of other factors will also be discussed; for example we know that the ECMWF model exhibits different skill levels for different regime transitions. It will also be shown that the new higher resolution ECMWF forecast system, then running in trial mode, performed somewhat better, at least for some of these cases.
Testing of Hypothesis in Equivalence and Non Inferiority Trials-A Concept.
Juneja, Atul; Aggarwal, Abha R; Adhikari, Tulsi; Pandey, Arvind
2016-04-01
Establishing the appropriate hypothesis is one of the important steps for carrying out the statistical tests/analysis. Its understanding is important for interpreting the results of statistical analysis. The current communication attempts to provide the concept of testing of hypothesis in non inferiority and equivalence trials, where the null hypothesis is just reverse of what is set up for conventional superiority trials. It is similarly looked for rejection for establishing the fact the researcher is intending to prove. It is important to mention that equivalence or non inferiority cannot be proved by accepting the null hypothesis of no difference. Hence, establishing the appropriate statistical hypothesis is extremely important to arrive at meaningful conclusion for the set objectives in research.
Early Reconstructions of Complex Lower Extremity Battlefield Soft Tissue Wounds
Ebrahimi, Ali; Nejadsarvari, Nasrin; Ebrahimi, Azin; Rasouli, Hamid Reza
2017-01-01
BACKGROUND Severe lower extremity trauma as a devastating combat related injury is on the rise and this presents reconstructive surgeons with significant challenges to reach optimal cosmetic and functional outcomes. This study assessed early reconstructions of complex lower extremity battlefield soft tissue wounds. METHODS This was a prospective case series study of battled field injured patients which was done in the Department of Plastic Surgery, Baqiyatallah University of Medical Sciences hospitals, Tehran, Iran between 2013-2015. In this survey, 73 patients were operated for reconstruction of lower extremity soft tissue defects due to battlefield injuries RESULTS Seventy-three patients (65 men, 8 womens) ranging from 21-48 years old (mean: 35 years) were enrolled. Our study showed that early debridement and bone stabilization and later coverage of complex battlefields soft tissue wounds with suitable flaps and grafts of lower extremity were effective method for difficult wounds managements with less amputation and infections. CONCLUSION Serial debridement and bone stabilization before early soft tissue reconstruction according to reconstructive ladder were shown to be essential steps. PMID:29218283
[Invariants of the anthropometrical proportions].
Smolianinov, V V
2012-01-01
In this work a general interpretation of a modulor as scales of segments proportions of anthropometrical modules (extremities and a body) is made. The objects of this study were: 1) to reason the idea of the growth modulor; 2) using the modern empirical data, to prove the validity of a principle of linear similarity for anthropometrical segments; 3) to specify the system of invariants for constitutional anthropometrics.
Christopher D. O' Connor; David E. Calkin; Matthew P. Thompson
2017-01-01
During active fire incidents, decisions regarding where and how to safely and effectively deploy resources to meet management objectives are often made under rapidly evolving conditions, with limited time to assess management strategies or for development of backup plans if initial efforts prove unsuccessful. Under all but the most extreme fire weather conditions,...
2000-06-23
conductivity ( NDC ) effects in double barrier resonant tunneling structures (DBRTS) prove the extremely fast frequency response of charge transport (less...UNCLASSIFIED Defense Technical Information Center Compilation Part Notice ADP013131 TITLE: Multiple-Barrier Resonant Tunneling Structures for...Institute Multiple-barrier resonant tunneling structures for application in a microwave generator stabilized by microstrip resonator S. V. Evstigneev, A. L
Territorial Developments Based on Graffiti: a Statistical Mechanics Approach
2011-10-28
defined on a lattice . We introduce a two-gang Hamiltonian model where agents have red or blue affiliation but are otherwise indistinguishable. In this...ramifications of our results. Keywords: Territorial Formation, Spin Systems, Phase Transitions 1. Introduction Lattice models have been extensively used in...inconsequential. In short, lattice models have proved extremely useful in the context of the physical, biological and even chemical sciences. In more
Pulsed magnetotherapy in Czechoslovakia--a review.
Jerabek, J
1994-01-01
Pulsed magnetotherapy has been used in Czechoslovakia for more than one decade. It has been proved that this type of physical therapy is very efficient mainly in rheumatic diseases, in paediatrics (sinusitis, enuresis), and in balneological care of patients suffering from ischaemic disorders of lower extremities. Promising results have also been obtained in neurological diseases (multiple sclerosis, spastic conditions) and in ophthalmology, in degenerative diseases of the retina.
1975-10-01
Decomposition of fluorodinitroethanol 15 — i<’*<<>mmtmmmmmmt^mm aoceie^s wW ** ^.^ -cUo. t^«t»-, « U.t a „«til reaction temperature U the...by formaldehyde make difficult to study this reaction quantitatively. Eplchlorohydrin homologues containing better leaving groups than chlorine ...dealt with study of reaction variables with emphasis of Im- proving the yield of l,3-blB(fluorodinltroethoxy)isopropanol, the key-inter- mediate, from
of plasma membranes of eukaryotic cells in vitro and in vivo. The physical to biological driving mechanisms behind nanoporation still remain unclear...but could be a result of a multitude of stimuli, including mechanical (shockwaves, electrode formation), thermal, and electrical (ion transport...channel gating). Experimentally quantifying and characterizing mechanical fields with piezoelectric transducers proves difficult due to electromagnetic
2010-08-01
word of mouth . CIVILIAN LEADERSHIP A-5. Local civil authorities normally can be found at these locations: Local town hall (local government...Combined Arms Doctrine Directorate at (913) 684-4884; or by e-mail to: leav-cadd-web- cadd@conus.army.mil; or submit an electronic DA Form 2028. 20...Pandemic influenza, for example refers to an influenza virus that infects humans across a large area and proves very difficult to contain. The word
The Strategic Utility of U.S. Navy SEALs
2009-06-01
USA Swimming, rugby organizations and wrestling organizations. In addition, while the demographics do not fully support it, the Navy and NSW put a...guerrilla 66 forces mainly against the Soviet Union (Waller, 1994). Recognizing the successes of the OSS and its ability to effectively work with...operations. This improved both forces capabilities and proved a very useful union . 78 SEALs are capable of this SFA mission, but it is a difficult
ERIC Educational Resources Information Center
Simmonds, Mark C.; Higgins, Julian P. T.; Stewart, Lesley A.
2013-01-01
Meta-analysis of time-to-event data has proved difficult in the past because consistent summary statistics often cannot be extracted from published results. The use of individual patient data allows for the re-analysis of each study in a consistent fashion and thus makes meta-analysis of time-to-event data feasible. Time-to-event data can be…
ERIC Educational Resources Information Center
Brown, Chris; Zhang, Dell
2016-01-01
Purpose: Whilst beneficial, the use of evidence to improve teaching and learning in schools is proving difficult to achieve in practice. The purpose of this paper is to shed new light on this issue by examining the applicability of a model of rational behaviour as relates to the notion of evidence-informed practice (EIP). Specifically, exploring…
2007-05-24
TYPE 3. DATES COVERED (From - To) 4. TITLE AND SUBTITLE 5a. CONTRACT NUMBER 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 5d. PROJECT NUMBER 5e...and X-Ray devices to detect radioactivity . All these systems would provide much needed air support and detection systems that would previously be...dangerous for manned aircraft to provide or would prove too difficult for ground vehicles to get to. These sampling techniques could also be used for
Panasonic Small Cell Testing for AHPS
NASA Technical Reports Server (NTRS)
Pearson, C.; Blackmore, P.; Lain, M.; Walpole, A.; Darcy, Eric
2006-01-01
AEA selection and successful Interim Design Review for AHPS proves maturity of small cell approach for very large batteries. Cells show excellent opportunity for battery mass reduction for AHPS and other low cycle applications. Lack of cycle and extended calendar life make EOL battery performance difficult (AHPS 8 year mission). Preliminary design, AEA retained SONY 18650HC cell as baseline: a) Well characterized performance; b) Wealth of safety test data.
Feasibility of a school reintegration programme for children with acute lymphoblastic leukaemia.
Annett, R D; Erickson, S J
2009-07-01
Despite children with acute lymphoblastic leukaemia missing a significant amount of school, little empirical literature guides the optimal content, setting and timing of a school reintegration programme. We examined the feasibility of a 4-month school reintegration intervention by: (1) developing collaboration with a community-based advocacy organisation; (2) developing intervention modules and observable end points; and (3) determining how the study achieved recruitment expectations. Eight families with children aged 6-12 years diagnosed with acute lymphoblastic leukaemia and parents were enrolled in the study. An experienced advocate implemented a series of eight modules over a 4-month period (twice per month) with the families. Participants completed pre-post measures. Successful collaboration with the advocacy organisation and the development of an intervention module series were achieved. Recruitment aims proved more difficult: enrolment was extended when recruitment for the original 1- to 6-month post-diagnosis window proved difficult. The advocate was able to complete between three and seven of the modules (mean = 5.2, standard deviation = 1.5). Families preferred clinic-based intervention. Challenges faced and lessons learned include: (1) advocacy organisations may be useful resources for school reintegration interventions; (2) school reintegration interventions must be flexibly applied; and (3) measurement end points constructed to gauge programme effectiveness.
Buckley, Lauren B; Huey, Raymond B
2016-12-01
Extreme temperatures can injure or kill organisms and can drive evolutionary patterns. Many indices of extremes have been proposed, but few attempts have been made to establish geographic patterns of extremes and to evaluate whether they align with geographic patterns in biological vulnerability and diversity. To examine these issues, we adopt the CLIMDEX indices of thermal extremes. We compute scores for each index on a geographic grid during a baseline period (1961-1990) and separately for the recent period (1991-2010). Heat extremes (temperatures above the 90th percentile during the baseline period) have become substantially more common during the recent period, particularly in the tropics. Importantly, the various indices show weak geographic concordance, implying that organisms in different regions will face different forms of thermal stress. The magnitude of recent shifts in indices is largely uncorrelated with baseline scores in those indices, suggesting that organisms are likely to face novel thermal stresses. Organismal tolerances correlate roughly with absolute metrics (mainly for cold), but poorly with metrics defined relative to local conditions. Regions with high extreme scores do not correlate closely with regions with high species diversity, human population density, or agricultural production. Even though frequency and intensity of extreme temperature events have - and are likely to have - major impacts on organisms, the impacts are likely to be geographically and taxonomically idiosyncratic and difficult to predict. © 2016 John Wiley & Sons Ltd.
Transition. Practice Perspectives--Highlighting Information on Deaf-Blindness. Number 4
ERIC Educational Resources Information Center
Malloy, Peggy; McGinnity, Betsy
2009-01-01
Finding a job, learning to live independently, and obtaining further education are important goals for all young adults as they leave high school. But achieving these goals is often extremely difficult for students who are deaf-blind. Limited or absent hearing and vision, difficulties with communication, and the frequent presence of additional…
An Extreme Case of Action Learning at BAT Niemeyer
ERIC Educational Resources Information Center
Eckstein, Emiel; Veenhoven, Gert; De Loo, Ivo
2009-01-01
Becoming a "winning organization" when one currently is an "ugly ducking" can be a difficult and strenuous task. BAT Niemeyer in the Netherlands succeeded in making such a transformation over the course of four years. Action learning was used, among other methods, to steer part of this transformation, in which employee…
Information and knowledge management in support of sustainable forestry: a review
H. Michael Rauscher; Daniel L. Schmoldt; Harald Vacik
2007-01-01
For individuals, organizations and nations, success and even survival depend upon making good decisions. Doing so can be extremely difficult when problems are not well structured and situations are complex, as they are for natural resource management. Recent advances in computer technology coupled with the increase in accessibility brought about by the...
Open Access, Retention and Throughput at the Central University of Technology
ERIC Educational Resources Information Center
de Beer, K. J.
2006-01-01
The most debatable question in higher education today is: Why first "open access" to promote massafication and now "capping" to restrict learner intake? (cf. SA Media Information 2004). Concerning the managing of this difficult and extremely sensitive issue, the Central University of Technology, Free State (CUT) has come a long…
Training Programs That Facilitate Lasting Change in Student Academic Behaviour
ERIC Educational Resources Information Center
Hodge, Brad
2014-01-01
A range of evidence suggests that changing a person's pattern of behaviour is extremely difficult, with past behaviour being one of the strongest predictors of future behaviour. This is particularly evident in the university setting where students tend to use the same academic processes they have used throughout their schooling despite any…
Personal Experiences of the Criminal Justice System by Individuals with Autism Spectrum Disorders
ERIC Educational Resources Information Center
Helverschou, Sissel Berge; Steindal, Kari; Nøttestad, Jim Aage; Howlin, Patricia
2018-01-01
The processes of arrest, investigation, trial and imprisonment are often extremely difficult for individuals with autism spectrum disorders. In this study, nine offenders with autism spectrum disorders were interviewed about the circumstance surrounding the criminal acts, their views of the arrest, the police interrogation, the trial and the…
Mining Formative Evaluation Rules Using Web-Based Learning Portfolios for Web-Based Learning Systems
ERIC Educational Resources Information Center
Chen, Chih-Ming; Hong, Chin-Ming; Chen, Shyuan-Yi; Liu, Chao-Yu
2006-01-01
Learning performance assessment aims to evaluate what knowledge learners have acquired from teaching activities. Objective technical measures of learning performance are difficult to develop, but are extremely important for both teachers and learners. Learning performance assessment using learning portfolios or web server log data is becoming an…
How Can "Problem Subjects" Be Made Less of a Problem?
ERIC Educational Resources Information Center
Warwick, Philip; Ottewill, Roger
2004-01-01
Many higher education courses, across the whole range of disciplines, include subjects that are somewhat problematic because they appear to be unrelated to other components of the curriculum. Students frequently perceive them as irrelevant and boring. This makes it extremely difficult for lecturers to stimulate interest and results in an…
The Coach-Team Approach: An Introductory Accounting Instructional Alternative
ERIC Educational Resources Information Center
Wood, Lynette I.
2012-01-01
Many students approach the introductory accounting course with a great deal of apprehension. For the most part, the course is populated by non-accounting majors who often perceive accounting to be extremely difficult and may view the instructor-student relationship as adversarial. As a result, such students may be inclined to express their…
ERIC Educational Resources Information Center
Price, Kelly; Price, Julia
2016-01-01
When digitally marketing an online educational program, degree or course, an institution must realize the target market which it is trying to reach. However, the demographics of the online student is extremely diverse, making marketing efforts difficult. With such a demographically diverse online student population to attract, it is important to…
Free metal ions are usually the most bioavailable and toxic metal species to aquatic organisms, but they are difficult to measure because of their extremely low concentrations in the marine environment. Many of the current methods for determining free metal ions are complicated a...
Fire behavior sensor package remote trigger design
Dan Jimenez; Jason Forthofer; James Reardon; Bret Butler
2007-01-01
Fire behavior characteristics (such as temperature, radiant and total heat flux, 2- and 3-dimensional velocities, and air flow) are extremely difficult to measure insitu. Although insitu sensor packages are capable of such measurements in realtime, it is also essential to acquire video documentation as a means of better understanding the fire behavior data recorded by...
Teaching and Learning: Hokie Spirit
ERIC Educational Resources Information Center
Lindeman, Cheryl A.
2007-01-01
If teachers were to reflect about their most difficult teachable moments in their careers, the author is sure the Virginia Tech tragedy would be extremely taxing on their minds. For those teachers teaching high school seniors, who were in the process of sending deposits to Virginia Tech, it was particularly agonizing. In this article, the author…
Guo, LanJun; Li, Yan; Han, Ruquan; Gelb, Adrian W
2018-01-01
Motor evoked potentials (MEPs) are commonly used during surgery for spinal cord tumor resection. However, it can be difficult to record reliable MEPs from the muscles of the lower extremities during surgery in patients with preoperative weakness due to spinal cord compression. In this study, motor function of patients' lower extremities and their association with intraoperative MEP recording were compared. Patients undergoing thoracic spinal cord tumor resection were studied. Patients' motor function was checked immediately before the surgical procedure. MEP responses were recorded from the tibialis anterior and foot muscles, and the hand muscles were used as control. Electrical current with train of eight pulses, 200 to 500 V was delivered through 2 corkscrews placed at C3' and C4' sites. Anesthesia was maintained by total intravenous anesthesia using a combination of propofol and remifentanil after induction with intravenous propofol, remifentanil, and rocuronium. Rocuronium was not repeated. Bispectral Index was maintained between 40 to 50. From 178 lower limbs of 89 patients, myogenic MEPs could be recorded from 100% (105/105) of the patients with 5 of 5 motor strength in lower extremity; 90% (36/40) from the patients with 4/5 motor strength; only 25% (5/20) with 3/5; and 12.5% (1/8) with 2/5 motor strength; none (0/5) were able to be recorded if the motor strength was 1/5. The ability to record myogenic MEPs is closely associated with the patient's motor function. They are difficult to obtain if motor function is 3/5 motor strength in the lower extremity. They are almost impossible to record if motor function is worse than 3/5.
Computational discovery of extremal microstructure families
Chen, Desai; Skouras, Mélina; Zhu, Bo; Matusik, Wojciech
2018-01-01
Modern fabrication techniques, such as additive manufacturing, can be used to create materials with complex custom internal structures. These engineered materials exhibit a much broader range of bulk properties than their base materials and are typically referred to as metamaterials or microstructures. Although metamaterials with extraordinary properties have many applications, designing them is very difficult and is generally done by hand. We propose a computational approach to discover families of microstructures with extremal macroscale properties automatically. Using efficient simulation and sampling techniques, we compute the space of mechanical properties covered by physically realizable microstructures. Our system then clusters microstructures with common topologies into families. Parameterized templates are eventually extracted from families to generate new microstructure designs. We demonstrate these capabilities on the computational design of mechanical metamaterials and present five auxetic microstructure families with extremal elastic material properties. Our study opens the way for the completely automated discovery of extremal microstructures across multiple domains of physics, including applications reliant on thermal, electrical, and magnetic properties. PMID:29376124
Extreme Statistics of Storm Surges in the Baltic Sea
NASA Astrophysics Data System (ADS)
Kulikov, E. A.; Medvedev, I. P.
2017-11-01
Statistical analysis of the extreme values of the Baltic Sea level has been performed for a series of observations for 15-125 years at 13 tide gauge stations. It is shown that the empirical relation between value of extreme sea level rises or ebbs (caused by storm events) and its return period in the Baltic Sea can be well approximated by the Gumbel probability distribution. The maximum values of extreme floods/ebbs of the 100-year recurrence were observed in the Gulf of Finland and the Gulf of Riga. The two longest data series, observed in Stockholm and Vyborg over 125 years, have shown a significant deviation from the Gumbel distribution for the rarest events. Statistical analysis of the hourly sea level data series reveals some asymmetry in the variability of the Baltic Sea level. The probability of rises proved higher than that of ebbs. As for the magnitude of the 100-year recurrence surge, it considerably exceeded the magnitude of ebbs almost everywhere. This asymmetry effect can be attributed to the influence of low atmospheric pressure during storms. A statistical study of extreme values has also been applied to sea level series for Narva over the period of 1994-2000, which were simulated by the ROMS numerical model. Comparisons of the "simulated" and "observed" extreme sea level distributions show that the model reproduces quite satisfactorily extreme floods of "moderate" magnitude; however, it underestimates sea level changes for the most powerful storm surges.
Diagnosis, treatment, and rehabilitation of stress fractures in the lower extremity in runners
Kahanov, Leamor; Eberman, Lindsey E; Games, Kenneth E; Wasik, Mitch
2015-01-01
Stress fractures account for between 1% and 20% of athletic injuries, with 80% of stress fractures in the lower extremity. Stress fractures of the lower extremity are common injuries among individuals who participate in endurance, high load-bearing activities such as running, military and aerobic exercise and therefore require practitioner expertise in diagnosis and management. Accurate diagnosis for stress fractures is dependent on the anatomical area. Anatomical regions such as the pelvis, sacrum, and metatarsals offer challenges due to difficulty differentiating pathologies with common symptoms. Special tests and treatment regimes, however, are similar among most stress fractures with resolution between 4 weeks to a year. The most difficult aspect of stress fracture treatment entails mitigating internal and external risk factors. Practitioners should address ongoing risk factors to minimize recurrence. PMID:25848327
Dynamic behavior of particles in spacecraft
NASA Technical Reports Server (NTRS)
Perrine, B. S.
1981-01-01
The behavior of particles relative to a spacecraft frame of reference was examined. Significant spatial excursions of particles in space can occur relative to the spacecraft frame of reference as a result of drag deceleration of the vehicle. These vehicle excursions tend to be large as time increases. Thus, if the particle is required to remain in a specified volume, constraints may be required. Thus, for example, in levitation experiments it may be extremely difficult to turn off the forces of constraint which keep the particles in a specified region. This means experiments which are sensitive to disturbances may be very difficult to perform if perturbation forces are required to be absent.
Yuan, Shi-Min
2016-01-01
Fungal endocarditis is a rare and fatal condition. The Candida and Aspergillus species are the two most common etiologic fungi found responsible for fungal endocarditis. Fever and changing heart murmur are the most common clinical manifestations. Some patients may have a fever of unknown origin as the onset symptom. The diagnosis of fungal endocarditis is challenging, and diagnosis of prosthetic valve fungal endocarditis is extremely difficult. The optimum antifungal therapy still remains debatable. Treating Candida endocarditis can be difficult because the Candida species can form biofilms on native and prosthetic heart valves. Combined treatment appears superior to monotherapy. Combination of antifungal therapy and surgical debridement might bring about better prognosis. PMID:27737409
Yuan, Shi-Min
2016-01-01
Fungal endocarditis is a rare and fatal condition. The Candida and Aspergillus species are the two most common etiologic fungi found responsible for fungal endocarditis. Fever and changing heart murmur are the most common clinical manifestations. Some patients may have a fever of unknown origin as the onset symptom. The diagnosis of fungal endocarditis is challenging, and diagnosis of prosthetic valve fungal endocarditis is extremely difficult. The optimum antifungal therapy still remains debatable. Treating Candida endocarditis can be difficult because the Candida species can form biofilms on native and prosthetic heart valves. Combined treatment appears superior to monotherapy. Combination of antifungal therapy and surgical debridement might bring about better prognosis.
Sowers, Nicholas; Kovacs, George
2016-02-01
Difficulty with intubation is not uncommon in the emergency setting. Video laryngoscopes (VLs) are commonly used to manage the difficult airway in the emergency department (ED). Intubation using a flexible bronchoscope, while considered the gold standard for managing the anticipated difficult airway in the operating room, is not commonly used in the ED. We present a case describing VL-assisted flexible scope intubation performed in the ED as a novel feasible approach to managing the difficult airway. A 65-year-old male, post cardiac arrest, with multiple unsuccessful attempts at prehospital intubation had rapid sequence intubation (RSI) performed and, despite obtaining a view with a King Vision™ VL, the skilled operator was unable to advance the endotracheal tube (ETT). An Ambu™ aScope3 flexible intubating scope (FIS) was placed through the ETT loaded in the channel of the King Vision and advanced through the cords to a position proximal to the carina. The ETT was then advanced easily over the FIS and down the trachea. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Although video laryngoscopy is commonly used in the ED, intubation can prove difficult, despite having an adequate view of the glottis. Use of an FIS, however, through a channeled VL makes navigation of the ETT easier and facilitates tube advancement, which can be difficult with VL. Channeled VL-assisted use of an FIS is a viable option for managing the difficult airway. Copyright © 2016 Elsevier Inc. All rights reserved.
Numerical simulation of crystal fractionation in shergottite meteorites
NASA Astrophysics Data System (ADS)
Grimm, R. E.; McSween, H. Y., Jr.
Cumulus clinopyroxenes in the Shergotty and Zagami meteorites suggest crystal fractionation occurred, possibly by gravitative settling. Numerical models of this process in a nonconvecting environment argue that the small phenocrysts can segregate only under extreme conditions of cooling time or gravitational field strength. Since textures indicate that cooling time was not excessive, a large (planetary) g is required by these models, in agreement with other suggestions that the shergottite parent body may be Mars. Other calculations indicate that it is extremely difficult to produce the observed textures in a convecting environment, unless crystal setting occurred in a quiescent zone at the bottom of the magma chamber.
Numerical simulation of crystal fractionation in shergottite meteorites
NASA Technical Reports Server (NTRS)
Grimm, R. E.; Mcsween, H. Y., Jr.
1982-01-01
Cumulus clinopyroxenes in the Shergotty and Zagami meteorites suggest crystal fractionation occurred, possibly by gravitative settling. Numerical models of this process in a nonconvecting environment argue that the small phenocrysts can segregate only under extreme conditions of cooling time or gravitational field strength. Since textures indicate that cooling time was not excessive, a large (planetary) g is required by these models, in agreement with other suggestions that the shergottite parent body may be Mars. Other calculations indicate that it is extremely difficult to produce the observed textures in a convecting environment, unless crystal setting occurred in a quiescent zone at the bottom of the magma chamber.
A Yang-Mills field on the extremal Reissner-Nordström black hole
NASA Astrophysics Data System (ADS)
Bizoń, Piotr; Kahl, Michał
2016-09-01
We consider a spherically symmetric (magnetic) SU(2) Yang-Mills field propagating on the exterior of the extremal Reissner-Nordström black hole. Taking advantage of the conformal symmetry, we reduce the problem to the study of the Yang-Mills equation in a geodesically complete spacetime with two asymptotically flat ends. We prove the existence of infinitely many static solutions (two of which are found in closed form) and determine the spectrum of their linear perturbations and quasinormal modes. Finally, using the hyperboloidal approach to the initial value problem, we describe the process of relaxation to the static endstates of evolution, both stable (for generic initial data) and unstable (for codimension-one initial data).
Highly Thermal Conductive Nanocomposites
NASA Technical Reports Server (NTRS)
Sun, Ya-Ping (Inventor); Connell, John W. (Inventor); Veca, Lucia Monica (Inventor)
2015-01-01
Disclosed are methods for forming carbon-based fillers as may be utilized in forming highly thermal conductive nanocomposite materials. Formation methods include treatment of an expanded graphite with an alcohol/water mixture followed by further exfoliation of the graphite to form extremely thin carbon nanosheets that are on the order of between about 2 and about 10 nanometers in thickness. Disclosed carbon nanosheets can be functionalized and/or can be incorporated in nanocomposites with extremely high thermal conductivities. Disclosed methods and materials can prove highly valuable in many technological applications including, for instance, in formation of heat management materials for protective clothing and as may be useful in space exploration or in others that require efficient yet light-weight and flexible thermal management solutions.
Highly Thermal Conductive Nanocomposites
NASA Technical Reports Server (NTRS)
Sun, Ya-Ping (Inventor); Connell, John W. (Inventor); Veca, Lucia Monica (Inventor)
2017-01-01
Disclosed are methods for forming carbon-based fillers as may be utilized in forming highly thermal conductive nanocomposite materials. Formation methods include treatment of an expanded graphite with an alcohol/water mixture followed by further exfoliation of the graphite to form extremely thin carbon nanosheets that are on the order of between about 2 and about 10 nanometers in thickness. Disclosed carbon nanosheets can be functionalized and/or can be incorporated in nanocomposites with extremely high thermal conductivities. Disclosed methods and materials can prove highly valuable in many technological applications including, for instance, in formation of heat management materials for protective clothing and as may be useful in space exploration or in others that require efficient yet light-weight and flexible thermal management solutions.
Biology and applications of human minisatellite loci.
Armour, J A; Jeffreys, A J
1992-12-01
Highly repetitive minisatellites' include the most variable human loci described to date. They have proved invaluable in a wide variety of genetic analyses, and despite some controversies surrounding their practical implementation, have been extensively adopted in civil and forensic casework. Molecular analysis of internal allelic structure has provided detailed insights into the repeat-unit turnover mechanisms operating in germline mutations, which are ultimately responsible for the extreme variability seen at these loci.
No static bubbling spacetimes in higher dimensional Einstein–Maxwell theory
NASA Astrophysics Data System (ADS)
Kunduri, Hari K.; Lucietti, James
2018-03-01
We prove that any asymptotically flat static spacetime in higher dimensional Einstein–Maxwell theory must have no magnetic field. This implies that there are no static soliton spacetimes and completes the classification of static non-extremal black holes in this theory. In particular, these results establish that there are no asymptotically flat static spacetimes with non-trivial topology, with or without a black hole, in Einstein–Maxwell theory.
Post-traumatic diaphragmatic hernias - importance of basic radiographic investigations.
Mansoor, E
2013-05-03
This case presentation highlights important principles in the management of post-traumatic diaphragmatic hernia. A suggestive history should prompt early diagnosis even if the patient appears well. The chest radiograph, although not pathognomonic, is extremely useful in the detection of diaphragmatic hernia if accurately interpreted. Herniated bowel is at high risk of strangulation, especially in the presence of a 'ribbon sign'. Delayed operative intervention can prove fatal.
Extremity War Injuries: Current Management and Research Priorities
2012-01-01
sal- vage and amputation. The 13 articles generated from this symposium ad- dress these topics as well as multi- modal strategies for pain control...reconstruction, and reha- bilitation. The last seven articles of this supplement address lessons learned, outcomes measures, current strategies, and knowledge... bioburden , which has resulted in im- proved patient care. At the EWI VII Symposium, sev- eral research priorities were outlined in the areas of acute care
Cardiac tamponade due to umbilical venous catheter in the new born
Abdellatif, Mohamed; Ahmed, Ashfag; Alsenaidi, Khalfan
2012-01-01
With more and more extreme premature and very low-birth weight babies being resuscitated, umbilical central venous catheterisation is now being used more frequently in neonatal intensive care. The authors present a case of cardiac tamponade following umbilical venous catheterisation in a neonate, an uncommon, yet potentially fatal complication. The patient was diagnosed at the appropriate time by echocardiography and urgent pericardiocentesis proved lifesaving. PMID:22802560
DOE Office of Scientific and Technical Information (OSTI.GOV)
Mara, Nathan Allan; Bronkhorst, Curt Allan; Beyerlein, Irene Jane
2015-12-21
The intent of this research effort is to prove the hypothesis that: Through the employment of controlled processing parameters which are based upon integrated advanced material characterization and multi-physics material modeling, bulk nanolayered composites can be designed to contain high densities of preferred interfaces that can serve as supersinks for the defects responsible for premature damage and failure.
Command Wire Sensor Measurements
2012-09-01
coupled with the extreme harsh terrain has meant that few of these techniques have proved robust enough when moved from the laboratory to the field...to image stationary objects and does not accurately image moving targets. Moving targets can be seriously distorted and displaced from their true...battlefield and for imaging of fixed targets. Moving targets can be detected with a SAR if they have a Doppler frequency shift greater than the
Cyberdeterrence Between Nation-States: Plausible Strategy Or A Pipe Dream?
2011-01-01
those attempting to conduct the trace.5 It is important to appreciate that no single technical attribution tech- nique provides a panacea . Most...conducted diplomatic, economic, or military initiatives. This might be enough to convince the defending state’s leaders of the adversary state’s guilt ...probable guilt , even if based solely on circumstantial evidence, could prove extremely damaging to the aggressor state’s diplomatic and informational
EMCS Installation Follow-Up Study. Volume 2.
1984-03-01
softwaLe is currently being developed by Power;. 4. The system includc;s an equation processor which p~ovi,.’ arithmetic, logicaL, and timing...packages are actually written using the equation processor. 5. The system colorgraphics capability was demonstrated. The system can be operated...extremely important. The AsteroAI drawings were reviewed by the Navy only on a cursory basis. This proved to be inad- equate . 15. The specifications
Manikandan, Selvaraj; Balaji, Seetharaaman; Kumar, Anil; Kumar, Rita
2007-01-01
The molecular basis for the survival of bacteria under extreme conditions in which growth is inhibited is a question of great current interest. A preliminary study was carried out to determine residue pattern conservation among the antiporters of enteric bacteria, responsible for extreme acid sensitivity especially in Escherichia coli and Shigella flexneri. Here we found the molecular evidence that proved the relationship between E. coli and S. flexneri. Multiple sequence alignment of the gadC coded acid sensitive antiporter showed many conserved residue patterns at regular intervals at the N-terminal region. It was observed that as the alignment approaches towards the C-terminal, the number of conserved residues decreases, indicating that the N-terminal region of this protein has much active role when compared to the carboxyl terminal. The motif, FHLVFFLLLGG, is well conserved within the entire gadC coded protein at the amino terminal. The motif is also partially conserved among other antiporters (which are not coded by gadC) but involved in acid sensitive/resistance mechanism. Phylogenetic cluster analysis proves the relationship of Escherichia coli and Shigella flexneri. The gadC coded proteins are converged as a clade and diverged from other antiporters belongs to the amino acid-polyamine-organocation (APC) superfamily. PMID:21670792
Rosenblum, William I
2014-05-01
Before amyloid formation, peptides cleaved from the amyloid precursor protein (APP) exist as soluble oligomers. These are extremely neurotoxic. Their concentration is strongly correlated with synaptic impairment in animals and parallel cognitive decline in animals and humans. Clinical trials have largely been aimed at removing insoluble beta amyloid in senile plaques and have not reduced soluble load. Even treatment that should remove soluble oligomers has not consistently reduced the load. Failure to significantly improve cognition has frequently been attributed to failure of the amyloid hypothesis or to irreversible alteration in the brain. Instead, trial failures may be because of failure to significantly reduce load of toxic Aβ oligomers. Moreover, targeting only synthesis of Aβ peptides, only the oligomers themselves, or only the final insoluble amyloid may fail to significantly reduce soluble load because of the interrelationship between these 3 points in the amyloid cascade. Thus, treatments may fail unless trials target simultaneously all 3 points in the equation-"triple therapy". Cerebrospinal fluid analysis and other monitoring tools may in the future provide reliable measurement of soluble load. But currently, only analysis of autopsied brains can provide this data and thus enable proper evaluation and explanation of the outcome of clinical trials. These data are essential before attributing trial failures to the advanced nature of the disease or asserting that failures prove that the theory linking Alzheimer's disease to products of amyloid precursor protein is incorrect. Copyright © 2014 Elsevier Inc. All rights reserved.
Norton, G V; Novarini, J C
2007-06-01
Ultrasonic imaging in medical applications involves propagation and scattering of acoustic waves within and by biological tissues that are intrinsically dispersive. Analytical approaches for modeling propagation and scattering in inhomogeneous media are difficult and often require extremely simplifying approximations in order to achieve a solution. To avoid such approximations, the direct numerical solution of the wave equation via the method of finite differences offers the most direct tool, which takes into account diffraction and refraction. It also allows for detailed modeling of the real anatomic structure and combination/layering of tissues. In all cases the correct inclusion of the dispersive properties of the tissues can make the difference in the interpretation of the results. However, the inclusion of dispersion directly in the time domain proved until recently to be an elusive problem. In order to model the transient signal a convolution operator that takes into account the dispersive characteristics of the medium is introduced to the linear wave equation. To test the ability of this operator to handle scattering from localized scatterers, in this work, two-dimensional numerical modeling of scattering from an infinite cylinder with physical properties associated with biological tissue is calculated. The numerical solutions are compared with the exact solution synthesized from the frequency domain for a variety of tissues having distinct dispersive properties. It is shown that in all cases, the use of the convolutional propagation operator leads to the correct solution for the scattered field.
Pressure-induced stable BeN4 as a high-energy density material
NASA Astrophysics Data System (ADS)
Zhang, Shoutao; Zhao, Ziyuan; Liu, Lulu; Yang, Guochun
2017-10-01
Polynitrogens are the ideal rocket fuels or propellants. Due to strong triple N≡N bond in N2, the direct polymerization of nitrogen is rather difficult (i.e. extreme high temperature and high pressure). However, the use of nitrides as precursors or the reaction of N2 with other elements has been proved to be an effective way to obtain polynitrogens. Here, with assistance of the advanced first-principles swarm-intelligence structure searches, we found that P 1 bar -BeN4, containing infinite zigzag-like polymeric nitrogen chains, can be synthesized by compressing the mixture of Be3N2 and N2 at 25.4 GPa, which is greatly lower than 110 GPa for synthesizing cubic gauche nitrogen and other polynitrogen compounds (e.g. bulk CNO at 52 GPa and SN4 at 49 GPa). Its structural stability can be attributed to the coexistence of ionic Be-N and covalent N-N bonds. Intriguingly, this phase has high kinetic stability and remains metastable at ambient pressure. The exceptional properties, including high energy density (3.60 kJ g-1), high nitrogen content (86.1%), high dynamical stability, and low polymerization pressure, make P 1 bar -structured BeN4 a promising high energy material. Infinite nitrogen chains in P 1 bar -BeN4 transform to N10 rings network in P21/c phase at 115.1 GPa. P 1 bar -BeN4 is metallic, while P21/c-BeN4 is an insulator.
Patel, B; Kirkwood, A A; Dey, A; Marks, D I; McMillan, A K; Menne, T F; Micklewright, L; Patrick, P; Purnell, S; Rowntree, C J; Smith, P; Fielding, A K
2017-01-01
Safety and efficacy data on pegylated asparaginase (PEG-ASP) in adult acute lymphoblastic leukaemia (ALL) induction regimens are limited. The UK National Cancer Research Institute UKALL14 trial NCT01085617 prospectively evaluated the tolerability of 1000 IU/m 2 PEG-ASP administered on days 4 and 18 as part of a five-drug induction regimen in adults aged 25-65 years with de novo ALL. Median age was 46.5 years. Sixteen of the 90 patients (median age 56 years) suffered treatment-related mortality during initial induction therapy. Eight of the 16 died of sepsis in combination with hepatotoxicity. Age and Philadelphia (Ph) status were independent variables predicting induction death >40 versus ⩽40 years, odds ratio (OR) 18.5 (2.02-169.0), P=0.01; Ph- versus Ph+ disease, OR 13.60 (3.52-52.36), P<0.001. Of the 74 patients who did not die, 37 (50.0%) experienced at least one grade 3/4 PEG-ASP-related adverse event, most commonly hepatotoxicity (36.5%, n=27). A single dose of PEG-ASP achieved trough therapeutic enzyme levels in 42/49 (86%) of the patients tested. Although PEG-ASP delivered prolonged asparaginase activity in adults, it was difficult to administer safely as part of the UKALL14 intensive multiagent regimen to those aged >40 years. It proved extremely toxic in patients with Ph+ ALL, possibly owing to interaction with imatinib.
Yack, Tina M; Barlow, Jay; Calambokidis, John; Southall, Brandon; Coates, Shannon
2013-09-01
Beaked whales are diverse and species rich taxa. They spend the vast majority of their time submerged, regularly diving to depths of hundreds to thousands of meters, typically occur in small groups, and behave inconspicuously at the surface. These factors make them extremely difficult to detect using standard visual survey methods. However, recent advancements in acoustic detection capabilities have made passive acoustic monitoring (PAM) a viable alternative. Beaked whales can be discriminated from other odontocetes by the unique characteristics of their echolocation clicks. In 2009 and 2010, PAM methods using towed hydrophone arrays were tested. These methods proved highly effective for real-time detection of beaked whales in the Southern California Bight (SCB) and were subsequently implemented in 2011 to successfully detect and track beaked whales during the ongoing Southern California Behavioral Response Study. The three year field effort has resulted in (1) the successful classification and tracking of Cuvier's (Ziphius cavirostris), Baird's (Berardius bairdii), and unidentified Mesoplodon beaked whale species and (2) the identification of areas of previously unknown beaked whale habitat use. Identification of habitat use areas will contribute to a better understanding of the complex relationship between beaked whale distribution, occurrence, and preferred habitat characteristics on a relatively small spatial scale. These findings will also provide information that can be used to promote more effective management and conservation of beaked whales in the SCB, a heavily used Naval operation and training region.
NASA Technical Reports Server (NTRS)
Harrell, Shelley; Zaretsky, Erwin V.
1961-01-01
The crystals of Pyroceram are randomly oriented and highly reflective so that standard microscopy techniques are not satisfactory for studying this material. Standard replicating procedures proved difficult to use. New microscopy techniques and procedures have therefore been developed. A method for locating, orienting, and identifying specific areas to be viewed with an electron microscope is described. This method not require any special equipment. Plastic replicas were found to be unsatisfactory because of their tendency to adhere to Pryoceram. This caused them to tear when released or resulted in artifacts. Preshadowed silicon monoxide replicas were satisfactory but required a releasing agent. A method of depositing the releasing agent is described. To polish specimens without evidence of fire-polishing, it was found necessary to use a vibratory polishing technique. Chrome oxide was used as the abrasive and either water or kerosene as the lubricant. Vibratory polishing is extremely slow, but surfaces so polished show no evidence of fire polishing, even when examined by electron microscopy. The most satisfactory etching process used for Pyroceram 9608 consisted of a primary etch of 5 milliliters of hydrochloric acid (concentrated), 5 milliliters of hydrogen fluoride (45 percent), and 45 milliliters of water, and a secondary etch with methyl alcohol replacing the water. Best results were obtained with total etching times from 25 to 30 seconds. Staining of the Pyroceram surface with a Sanford's marker was found to be an expedient way to reduce the glare of reflected light.
Patel, B; Kirkwood, A A; Dey, A; Marks, D I; McMillan, A K; Menne, T F; Micklewright, L; Patrick, P; Purnell, S; Rowntree, C J; Smith, P; Fielding, A K
2017-01-01
Safety and efficacy data on pegylated asparaginase (PEG-ASP) in adult acute lymphoblastic leukaemia (ALL) induction regimens are limited. The UK National Cancer Research Institute UKALL14 trial NCT01085617 prospectively evaluated the tolerability of 1000 IU/m2 PEG-ASP administered on days 4 and 18 as part of a five-drug induction regimen in adults aged 25–65 years with de novo ALL. Median age was 46.5 years. Sixteen of the 90 patients (median age 56 years) suffered treatment-related mortality during initial induction therapy. Eight of the 16 died of sepsis in combination with hepatotoxicity. Age and Philadelphia (Ph) status were independent variables predicting induction death >40 versus ⩽40 years, odds ratio (OR) 18.5 (2.02–169.0), P=0.01; Ph− versus Ph+ disease, OR 13.60 (3.52–52.36), P<0.001. Of the 74 patients who did not die, 37 (50.0%) experienced at least one grade 3/4 PEG-ASP-related adverse event, most commonly hepatotoxicity (36.5%, n=27). A single dose of PEG-ASP achieved trough therapeutic enzyme levels in 42/49 (86%) of the patients tested. Although PEG-ASP delivered prolonged asparaginase activity in adults, it was difficult to administer safely as part of the UKALL14 intensive multiagent regimen to those aged >40 years. It proved extremely toxic in patients with Ph+ ALL, possibly owing to interaction with imatinib. PMID:27480385
Molecular detection of trophic links in a complex insect host-parasitoid food web.
Hrcek, Jan; Miller, Scott E; Quicke, Donald L J; Smith, M Alex
2011-09-01
Previously, host-parasitoid links have been unveiled almost exclusively by time-intensive rearing, while molecular methods were used only in simple agricultural host-parasitoid systems in the form of species-specific primers. Here, we present a general method for the molecular detection of these links applied to a complex caterpillar-parasitoid food web from tropical rainforest of Papua New Guinea. We DNA barcoded hosts, parasitoids and their tissue remnants and matched the sequences to our extensive library of local species. We were thus able to match 87% of host sequences and 36% of parasitoid sequences to species and infer subfamily or family in almost all cases. Our analysis affirmed 93 hitherto unknown trophic links between 37 host species from a wide range of Lepidoptera families and 46 parasitoid species from Hymenoptera and Diptera by identifying DNA sequences for both the host and the parasitoid involved in the interaction. Molecular detection proved especially useful in cases where distinguishing host species in caterpillar stage was difficult morphologically, or when the caterpillar died during rearing. We have even detected a case of extreme parasitoid specialization in a pair of Choreutis species that do not differ in caterpillar morphology and ecology. Using the molecular approach outlined here leads to better understanding of parasitoid host specificity, opens new possibilities for rapid surveys of food web structure and allows inference of species associations not already anticipated. Published 2011. This article is a US Government work and is in the public domain in the USA.
Vulnerability of children and the developing brain to neurotoxic hazards.
Weiss, B
2000-06-01
For much of the history of toxicology, the sensitivity of the developing organism to chemical perturbation attracted limited attention. Several tragic episodes and new insights finally taught us that the course of early brain development incurs unique risks. Although the process is exquisitely controlled, its lability renders it highly susceptible to damage from environmental chemicals. Such disturbances, as recognized by current testing protocols and legislation such as the Food Quality Protection Act, can result in outcomes ranging from death to malformations to functional impairment. The latter are the most difficult to determine. First, they require a variety of measures to assay their extent. Second, adult responses may prove an inadequate guide to the response of the developing brain, which is part of the reason for proposing additional safety factors for children. Third, neuropsychological tests are deployed in complex circumstances in which many factors, including economic status, combine to produce a particular effect such as lowered intelligence quotient score. Fourth, the magnitude of the effect, for most environmental exposure levels, may be relatively small but extremely significant for public health. Fifth, changes in brain function occur throughout life, and some consequences of early damage may not even emerge until advanced age. Such factors need to be addressed in estimating the influence of a particular agent or group of agents on brain development and its functional expression. It is especially important to consider ways of dealing with multiple risks and their combinations in addition to the prevailing practice of estimating risks in isolation.
NASA Astrophysics Data System (ADS)
Boden, Seth; Karam, P.; Schmidt, A.; Pennathur, S.
2017-05-01
Fused silica is an ideal material for nanofluidic systems due to its extreme purity, chemical inertness, optical transparency, and native hydrophilicity. However, devices requiring embedded electrodes (e.g., for bioanalytical applications) are difficult to realize given the typical high temperature fusion bonding requirements (˜1000 °C). In this work, we optimize a two-step plasma activation process which involves an oxygen plasma treatment followed by a nitrogen plasma treatment to increase the fusion bonding strength of fused silica at room temperature. We conduct a parametric study of this treatment to investigate its effect on bonding strength, surface roughness, and microstructure morphology. We find that by including a nitrogen plasma treatment to the standard oxygen plasma activation process, the room temperature bonding strength increases by 70% (0.342 J/m2 to 0.578 J/m2). Employing this optimized process, we fabricate and characterize a nanofluidic device with an integrated and dielectrically separated electrode. Our results prove that the channels do not leak with over 1 MPa of applied pressure after a 24 h storage time, and the electrode exhibits capacitive behavior with a finite parallel resistance in the upper MΩ range for up to a 6.3Vdc bias. These data thus allow us to overcome the barrier that has barred nanofluidic progress for the last decade, namely, the development of nanometer scale well-defined channels with embedded metallic materials for far-reaching applications such as the exquisite manipulation of biomolecules.
A dusty, normal galaxy in the epoch of reionization.
Watson, Darach; Christensen, Lise; Knudsen, Kirsten Kraiberg; Richard, Johan; Gallazzi, Anna; Michałowski, Michał Jerzy
2015-03-19
Candidates for the modest galaxies that formed most of the stars in the early Universe, at redshifts z > 7, have been found in large numbers with extremely deep restframe-ultraviolet imaging. But it has proved difficult for existing spectrographs to characterize them using their ultraviolet light. The detailed properties of these galaxies could be measured from dust and cool gas emission at far-infrared wavelengths if the galaxies have become sufficiently enriched in dust and metals. So far, however, the most distant galaxy discovered via its ultraviolet emission and subsequently detected in dust emission is only at z = 3.2 (ref. 5), and recent results have cast doubt on whether dust and molecules can be found in typical galaxies at z ≥ 7. Here we report thermal dust emission from an archetypal early Universe star-forming galaxy, A1689-zD1. We detect its stellar continuum in spectroscopy and determine its redshift to be z = 7.5 ± 0.2 from a spectroscopic detection of the Lyman-α break. A1689-zD1 is representative of the star-forming population during the epoch of reionization, with a total star-formation rate of about 12 solar masses per year. The galaxy is highly evolved: it has a large stellar mass and is heavily enriched in dust, with a dust-to-gas ratio close to that of the Milky Way. Dusty, evolved galaxies are thus present among the fainter star-forming population at z > 7.
Non-stabilized nucleophiles in Cu-catalysed dynamic kinetic asymmetric allylic alkylation
NASA Astrophysics Data System (ADS)
You, Hengzhi; Rideau, Emeline; Sidera, Mireia; Fletcher, Stephen P.
2015-01-01
The development of new reactions forming asymmetric carbon-carbon bonds has enabled chemists to synthesize a broad range of important carbon-containing molecules, including pharmaceutical agents, fragrances and polymers. Most strategies to obtain enantiomerically enriched molecules rely on either generating new stereogenic centres from prochiral substrates or resolving racemic mixtures of enantiomers. An alternative strategy--dynamic kinetic asymmetric transformation--involves the transformation of a racemic starting material into a single enantiomer product, with greater than 50 per cent maximum yield. The use of stabilized nucleophiles (pKa < 25, where Ka is the acid dissociation constant) in palladium-catalysed asymmetric allylic alkylation reactions has proved to be extremely versatile in these processes. Conversely, the use of non-stabilized nucleophiles in such reactions is difficult and remains a key challenge. Here we report a copper-catalysed dynamic kinetic asymmetric transformation using racemic substrates and alkyl nucleophiles. These nucleophiles have a pKa of >=50, more than 25 orders of magnitude more basic than the nucleophiles that are typically used in such transformations. Organometallic reagents are generated in situ from alkenes by hydrometallation and give highly enantioenriched products under mild reaction conditions. The method is used to synthesize natural products that possess activity against tuberculosis and leprosy, and an inhibitor of para-aminobenzoate biosynthesis. Mechanistic studies indicate that the reaction proceeds through a rapidly isomerizing intermediate. We anticipate that this approach will be a valuable complement to existing asymmetric catalytic methods.
Searching for Strange Quark Matter Objects in Exoplanets
DOE Office of Scientific and Technical Information (OSTI.GOV)
Huang, Y. F.; Yu, Y. B., E-mail: hyf@nju.edu.cn
2017-10-20
The true ground state of hadronic matter may be strange quark matter (SQM). Consequently, observed pulsars may actually be strange quark stars, but not neutron stars. However, proving or disproving the SQM hypothesis still remains a difficult problem to solve due to the similarity between the macroscopical characteristics of strange quark stars and neutron stars. Here, we propose a hopeful method to probe the existence of SQM. In the framework of the SQM hypothesis, strange quark dwarfs and even strange quark planets can also stably exist. Noting that SQM planets will not be tidally disrupted even when they get verymore » close to their host stars due to their extreme compactness, we argue that we could identify SQM planets by searching for very close-in planets among extrasolar planetary systems. Especially, we should keep our eyes on possible pulsar planets with orbital radius less than ∼5.6 × 10{sup 10} cm and period less than ∼6100 s. A thorough search in the currently detected ∼2950 exoplanets around normal main-sequence stars has failed to identify any stable close-in objects that meet the SQM criteria, i.e., lying in the tidal disruption region for normal matter planets. However, the pulsar planet PSR J1719-1438B, with an orbital radius of ∼6 × 10{sup 10} cm and orbital period of 7837 s, is, encouragingly, found to be a good candidate.« less
ERIC Educational Resources Information Center
Smith, Dorothy Veronica
2011-01-01
The past 20 years or so have seen ongoing concern for the nature of science education in the Anglophone developed world. A particular focus of this concern has been the need to find new ways to frame science curricula that will engage students, yet it is proving difficult to achieve this goal. In this article I argue that the impact on science…
ERIC Educational Resources Information Center
Brown, Chris; Zhang, Dell
2016-01-01
Whilst beneficial, the consistent and regular use of evidence to improve teaching and learning in schools is proving difficult to achieve in practice. This paper attempts to shed new light on this issue by examining the applicability of a model of rational behaviour as it relates to the notion of evidence-informed practice (EIP). Specifically,…
High Energy Density Polymer Film Capacitors
2006-10-01
abandoned when, under vacuum, a noticeable output frequency drift was observed, even when the tube ripple frequency was rejected by integrating over one...only minor circuitry and software changes. The selection of the light source proved more difficult. An earlier attempt to use a florescent tube was...bulb, which of course, led to a frequency drift interpretation by the sensor array (see graph 2). Even if the "self sputtering" behavior had not 14 been
DOE Office of Scientific and Technical Information (OSTI.GOV)
Bakst, R.H.; Kanat, I.O.
1987-11-01
Many complications can occur following insertion of silicone elastomer implants into the foot. Postoperative infection may be difficult to distinguish from other conditions such as dislodgment, fracture, ectopic and heterotopic new bone formation, synovitis, and bursitis. White blood cell scintigraphy, in conjunction with the clinical scenario, may prove to be an invaluable tool in the diagnosis of postoperative osteomyelitis, subsequent to implant arthroplasties. 32 references.
Airpower In The Information Age: Embracing TCP/IP Within Airborne Networks
2015-04-01
proved successful at seamlessly connecting large numbers of users to a vast array of applications. Airborne TCP/IP communication systems within DoD are...behind the development of next generation weapons systems. Admiral Fitzgerald recommends that the network architecture be developed and the...environment makes traditional ISR much more difficult and the military will need to rely on fifth- generation platforms like the F-35 that are able to
Atoms in molecules, an axiomatic approach. I. Maximum transferability
NASA Astrophysics Data System (ADS)
Ayers, Paul W.
2000-12-01
Central to chemistry is the concept of transferability: the idea that atoms and functional groups retain certain characteristic properties in a wide variety of environments. Providing a completely satisfactory mathematical basis for the concept of atoms in molecules, however, has proved difficult. The present article pursues an axiomatic basis for the concept of an atom within a molecule, with particular emphasis devoted to the definition of transferability and the atomic description of Hirshfeld.
[Caregivers of people with neurodegenerative diseases: from help to delegation].
Delzescaux, Sabine; Blondel, Frédéric
2015-01-01
Being a caregiver is difficult, even more so when it comes to helping people with a neurodegenerative disease. These caregivers, either family members or close friends, are confronted with an unexpected delegation which can prove to be highly complex as the pitfalls can indeed be significant. Moreover, the support the caregivers can provide depends on the support they can get for themselves. Copyright © 2015 Elsevier Masson SAS. All rights reserved.
The South Korean Model of Political and Economic Development: Economic Aspects.
1983-10-01
controls, future wage negotiations are likely to prove difficult as workers push to make up for earlier losses. Negotiations may even by destabilizing if 6... workers and reports of labor shortage during seasons of veak farm activity. Traditional labor abundance has evidently given way to shortage, and to...new entrants and more fully employ established workers . The dramatic reversal in output growth of 1979-80, sub- sequent industrial stagnation, and a
NASA Technical Reports Server (NTRS)
Cash, W.
1979-01-01
Many problems in the experimental estimation of parameters for models can be solved through use of the likelihood ratio test. Applications of the likelihood ratio, with particular attention to photon counting experiments, are discussed. The procedures presented solve a greater range of problems than those currently in use, yet are no more difficult to apply. The procedures are proved analytically, and examples from current problems in astronomy are discussed.
A half-truth is a whole lie: on the necessity of investigating sex influences on the brain.
Cahill, Larry
2012-06-01
Sex influences are proving to be extremely widespread on brain function, including the human brain. Ample evidence now proves that the sex of subjects can influence, ever reverse, findings, hence conclusions, at all levels of brain science, down to the molecular level, often in completely unanticipated ways. Thus the still-prominent assumption that sex influences may be safely ignored by neurobiologists is invalid and must be abandoned. The failure to properly consider the issue fills the literature with conclusions tenuous at best, false at worst. The continuing, widespread resistance to investigating sex influences among brain scientists, a resistance largely rooted in deeply entrenched biases against the topic, is becoming increasingly scientifically indefensible and strongly retards progress in our field.
Single crystal growth of Ga3Ni2 by the Czochralski method
NASA Astrophysics Data System (ADS)
Wencka, Magdalena; Pillaca, Mirtha; Gille, Peter
2016-09-01
Intermetallic compounds have proved to be interesting alternatives to heterogeneous catalysts prepared from pure noble metals or their alloys. As to study their intrinsic properties, to determine the crystalline structures of specific surfaces and finally to understand elementary processes of heterogeneous catalysis, single crystals of these intermetallics are needed. Inspired by the recent discovery of Ga-Ni catalysts for carbon dioxide reduction to methanol, we have grown for the first time cm3-size single crystals of trigonal Ga3Ni2. We report in detail on the synthesis and Czochralski growth from high-temperature solution using Ga as native solvent. Inclusion formation of Ga-rich fluid proved to be the most severe problem that was minimized by using an extremely low pulling rate down to 25 μm/h.
Managing Conflict with Direct Reports. For the Practicing Manager. An Ideas into Action Guidebook.
ERIC Educational Resources Information Center
Popejoy, Barbara; McManigle, Brenda J.
Conflict is inevitable when people work together because they have different points of view, values, and ways of working. Resolving conflicts can be extremely difficult because of these differences. This short guidebook addresses ways successful leaders can work to manage conflict in the workplace, in particular conflict with people who report to…
Alaska biological control program directed at amber-marked birch leaf miner.
J.E. Lundquist; K.F. Zogas; C.L. Snyder; B.K. Schulz
2008-01-01
Nonnative invasive insects are having major impacts on the economics and ecology of forests nationwide. Until recently, Alaska was fortunately mostly free of these pests. Because of the remoteness of much of Alaska's native forests, an invasive pest infestation would be extremely difficult to control. Global markets, global climate change, and the ever-increasing...
What Recourse for the Principal Abused by Community Activists? The Case of "Stevens v. Tillman."
ERIC Educational Resources Information Center
Menacker, Julius
1990-01-01
"Stevens v. Tillman" illustrates the limited reach of federal law in controversies where community activists use extreme, even illegal, methods to exert their will over objecting school officials. Defamation charges against activists for verbal abuses will apparently be very difficult to sustain, given court views that being called a…
USDA-ARS?s Scientific Manuscript database
Cynodon dactylon (L.) Pers. (common bermudagrass) is a troublesome perennial grass common in the southeastern U. S. and extremely difficult to control in organic crop production systems. Research trials in a site heavily infested with C. dactylon were conducted from 2008 to 2010 to evaluate systems...
Adaptive Techniques for Control of Large Space Structures.
1984-12-01
uncertainty, diverge and ultimately go unstable. This problem is extremely difficult and has only recently been addressed, even in the general context of...L. (4.7b) Corollary 1: Performance Bounds Suppose z. and e. satisfy the conditions in () of Theroems 1A or 18. I) Let H c SPR , i.e., - M, y > 0 such
The Impact of Social Software in Product Design Higher Education
ERIC Educational Resources Information Center
Hurn, Karl
2012-01-01
It is difficult to ignore the impact that Web 2.0 and the subsequent social software revolution has had on society in general, and young people in particular. Information is exchanged and interpreted extremely quickly and in ways that were not imagined 10 years ago. Universities are struggling to keep up with this new technology, with outdated…
A Simple Microscopy Assay to Teach the Processes of Phagocytosis and Exocytosis
ERIC Educational Resources Information Center
Gray, Ross; Gray, Andrew; Fite, Jessica L.; Jordan, Renee; Stark, Sarah; Naylor, Kari
2012-01-01
Phagocytosis and exocytosis are two cellular processes involving membrane dynamics. While it is easy to understand the purpose of these processes, it can be extremely difficult for students to comprehend the actual mechanisms. As membrane dynamics play a significant role in many cellular processes ranging from cell signaling to cell division to…
ERIC Educational Resources Information Center
Lavi, Iris; Slone, Michelle
2011-01-01
Children in countries involved in violent national conflicts experience difficult and, at times, extreme events such as spending long hours in shelters, witnessing terror attacks, or having a family member absent or injured while participating in battle. This study explores the moderating effect of resilience factors, self-esteem, and…
Visual impacts in the urban-wildland interface
Arthur W. Magill; Rowan A. Rowntree; Robert O. Brush
1979-01-01
The urban-wildland interface is treated as a place where extremes meet--where it is difficult to maintain a visually appealing transition from country to city. Problems are identified in relation to stable cities, urbanizing areas, and developing resorts in the wildlands. The visual problems of urbanization are also discussed in relation to physical impacts such as...
ERIC Educational Resources Information Center
Young, Nancy L.; Barden, Wendy S.; Mills, Wendy A.; Burke, Tricia A.; Law, Mary; Boydell, Katherine
2009-01-01
Introduction: The transition to adulthood is extremely difficult for individuals with disabilities. We sought to explore the specific issue of transition to adult-oriented health care in a Canadian context. Methods: We conducted semi-structured individual interviews with 15 youth and 15 adults with cerebral palsy, spina bifida, and acquired brain…
New technology in postfire rehab
Joe Sabel
2007-01-01
PAM-12⢠is a recycled office paper byproduct made into a spreadable mulch with added Water Soluble Polyacrylamide (WSPAM), a previously difficult polymer to apply. PAM-12 is extremely versatile and can be applied through several methods. In a field test, PAM-12 outperformed straw in every targeted performance area: erosion control, improving soil hydrophobicity, and...
2014-06-13
corruption and cheating. This also makes it extremely difficult to determine the actual impact on the resource and the entire ecosystem . “Overfishing...limits, established under international agreements. By adversely impacting fisheries, marine ecosystems , food security and coastal communities around...
ERIC Educational Resources Information Center
Smith, Mike U.
Both teachers and students alike acknowledge that genetics and genetics problem-solving are extremely difficult to learn and to teach. Therefore, a number of recommendations for teaching college genetics are offered. Although few of these ideas have as yet been tested in controlled experiments, they are supported by research and experience and may…
Libraries in Today's Digital Age: The Copyright Controversy. ERIC Digest.
ERIC Educational Resources Information Center
Russell, Carrie
This digest focuses on the continuing ambiguities libraries and their users face in dealing with copyright in the digital environment. In the networked digital world, the basic principles of copyright are more difficult to apply. Digital copies are easy to create, modify, and manipulate, they are extremely easy to distribute widely over networks,…
Denying Social Harm: Students' Resistance to Lessons about Inequality
ERIC Educational Resources Information Center
Kleinman, Sherryl; Copp, Martha
2009-01-01
Students share folk beliefs that make it difficult for them to understand inequality, especially the harmful consequences of social practices they routinely engage in, are attached to, and take for granted. Four of these beliefs include: (a) harm is direct, extreme, and the product of an individual's intentions; (2) harm is the product of the…
Heterotopic Prostate at Autopsy- An Unusual Mass at the Dome of the Urinary Bladder.
Munde, Shital; Fernandes, Gwendolyn; Phadnis, Priyanka
2017-09-01
Heterotopic prostate in the dome of the urinary bladder is extremely rare and difficult to diagnose. It is often mistaken for neoplastic masses and histopathological examination is warranted for diagnosis. We report an autopsy case of an ectopic prostate at the dome of the bladder which mimicked a neoplasm on gross pathology.
Teaching about the Holocaust--A Resource Guide
ERIC Educational Resources Information Center
Russell, William Benedict, III
2005-01-01
Teaching about the Holocaust is an emotional process that can be extremely difficult, especially without the proper resources. Most teachers spend one or two class periods on the Holocaust and usually cram the lesson into a unit on World War II. As a teacher, the author understands that time is short and that it is impossible to spend the…
Hardwood cover crops:can they enhance loblolly pine seedling production
Paul P. Kormanik; Shi-Jean S. Sung; T.L. Kormanik; Stanley J. Zarnoch
1995-01-01
It has been extremely difficult to obtain more than two loblolly pine (Pinus taeda L.) crops following even effective soil fumigation with methyl bromide in southern forest tree nurseries. The traditional agronomic cover crops such as sorghum and sudex, unless followed by fumigation, do not normally produce satisfactory loblolly pine seedling crops. Various species...
An Educational Game for Learning Human Immunology: What Do Students Learn and How Do They Perceive?
ERIC Educational Resources Information Center
Cheng, Meng-Tzu; Su, TzuFen; Huang, Wei-Yu; Chen, Jhih-Hao
2014-01-01
The scientific concepts of human immunology are inherently complicated and extremely difficult to understand. Hence, this study reports on the development of an educational game entitled "Humunology" and examines the impact of using "Humunology" for learning how the body's defense system works. A total of 132 middle school…
Joao A. N. Filipe; Richard C. Cobb; Ross K. Meentemeyer; Christopher A. Lee; Yana S. Valachovic; Alex R. Cook; David M. Rizzo; Christopher A. Gilligan
2012-01-01
Exotic pathogens and pests threaten ecosystem service, biodiversity, and crop security globally. If an invasive agent can disperse asymptomatically over long distances, multiple spatial and temporal scales interplay, making identification of effective strategies to regulate, monitor, and control disease extremely difficult. The management of outbreaks is also...
Chapter 19: The carbon isotope composition of plants and soils as biomarkers of pollution
DE Pataki; JT Eanderson; W Want; MK Herzenach; NE Grulke
2010-01-01
Urban environments have been compared to the global environment predicted at the end of the twenty-first century, in that urban areas are currently experiencing elevated atmospheric C02 concentrations, warmer temperatures, increased nitrogen loads, and elevated concentrations of pollutants (Grimm et al. 2000). It is extremely difficult to predict...
Learning in LAMS: Lesson from a Student Teacher Exploring Gene Ethics
ERIC Educational Resources Information Center
Dennis, Carina
2012-01-01
Due to its complex and microscopic nature, genetics is a difficult subject for many learners to conceptually grasp. Graphics, animation and video material can be extremely helpful to their understanding. A wealth of educational online content about genetics has been created over the past decade in the wake of the human genome being sequenced.…
Probabilistic forecasting for extreme NO2 pollution episodes.
Aznarte, José L
2017-10-01
In this study, we investigate the convenience of quantile regression to predict extreme concentrations of NO 2 . Contrarily to the usual point-forecasting, where a single value is forecast for each horizon, probabilistic forecasting through quantile regression allows for the prediction of the full probability distribution, which in turn allows to build models specifically fit for the tails of this distribution. Using data from the city of Madrid, including NO 2 concentrations as well as meteorological measures, we build models that predict extreme NO 2 concentrations, outperforming point-forecasting alternatives, and we prove that the predictions are accurate, reliable and sharp. Besides, we study the relative importance of the independent variables involved, and show how the important variables for the median quantile are different than those important for the upper quantiles. Furthermore, we present a method to compute the probability of exceedance of thresholds, which is a simple and comprehensible manner to present probabilistic forecasts maximizing their usefulness. Copyright © 2017 Elsevier Ltd. All rights reserved.
Cumulative hazard: The case of nuisance flooding
NASA Astrophysics Data System (ADS)
Moftakhari, Hamed R.; AghaKouchak, Amir; Sanders, Brett F.; Matthew, Richard A.
2017-02-01
The cumulative cost of frequent events (e.g., nuisance floods) over time may exceed the costs of the extreme but infrequent events for which societies typically prepare. Here we analyze the likelihood of exceedances above mean higher high water and the corresponding property value exposure for minor, major, and extreme coastal floods. Our results suggest that, in response to sea level rise, nuisance flooding (NF) could generate property value exposure comparable to, or larger than, extreme events. Determining whether (and when) low cost, nuisance incidents aggregate into high cost impacts and deciding when to invest in preventive measures are among the most difficult decisions for policymakers. It would be unfortunate if efforts to protect societies from extreme events (e.g., 0.01 annual probability) left them exposed to a cumulative hazard with enormous costs. We propose a Cumulative Hazard Index (CHI) as a tool for framing the future cumulative impact of low cost incidents relative to infrequent extreme events. CHI suggests that in New York, NY, Washington, DC, Miami, FL, San Francisco, CA, and Seattle, WA, a careful consideration of socioeconomic impacts of NF for prioritization is crucial for sustainable coastal flood risk management.
Moving beyond disrespect and abuse: addressing the structural dimensions of obstetric violence.
Sadler, Michelle; Santos, Mário Jds; Ruiz-Berdún, Dolores; Rojas, Gonzalo Leiva; Skoko, Elena; Gillen, Patricia; Clausen, Jette A
2016-05-01
During recent decades, a growing and preoccupying excess of medical interventions during childbirth, even in physiological and uncomplicated births, together with a concerning spread of abusive and disrespectful practices towards women during childbirth across the world, have been reported. Despite research and policy-making to address these problems, changing childbirth practices has proved to be difficult. We argue that the excessive rates of medical interventions and disrespect towards women during childbirth should be analysed as a consequence of structural violence, and that the concept of obstetric violence, as it is being used in Latin American childbirth activism and legal documents, might prove to be a useful tool for addressing structural violence in maternity care such as high intervention rates, non-consented care, disrespect and other abusive practices. Copyright © 2016 Elsevier Inc. All rights reserved.
Successes in drug discovery and design.
2004-04-01
The Society for Medicines Research (SMR) held a one-day meeting on case histories in drug discovery on December 4, 2003, at the National Heart and Lung Institute in London. These meetings have been organized by the SMR biannually for many years, and this latest meeting proved extremely popular, attracting a capacity audience of more than 130 registrants. The purpose of these meetings is educational; they allow those interested in drug discovery to hear key learnings from recent successful drug discovery programs. There was no overall linking theme between the talks, other than each success story has led to the introduction of a new and improved product of therapeutic use. The drug discovery stories covered in the meeting were extremely varied and, put together, they emphasized that each successful story is unique and special. This meeting is also special for the SMR because it presents the "SMR Award for Drug Discovery" in recognition of outstanding achievement and contribution in the area. It should be remembered that drug discovery is an extremely risky business and an extremely costly and complicated process in which the success rate is, at best, low. (c) 2004 Prous Science. All rights reserved.
Enhancement of the United States Naval Academy (USNA) Polar Science Program (PSP)
2013-09-30
buoy hull design was designed, modeled , and tested. And initial analysis was performed on the NAICEX snow and ice data by midshipmen. RESULTS...to help better understand how the IABP buoys are performing (Fig. 4). The near real time webcam information has proved extremely beneficial for... IABP ). Mishipman Julia Zook works with University of Washington Engineer Jim Johnson on the IK3T during her summer internship to Barrow, AK
Understanding the stability of surface nanobubbles.
Wang, Shuo; Liu, Minghuan; Dong, Yaming
2013-05-08
Surface nanobubbles emerging at solid-liquid interfaces show extreme stability. In this paper, the stability of surface nanobubbles in degassed water is discussed and investigated by AFM. The result demonstrates that surface nanobubbles are kinetically stable and the liquid/gas interface is gas impermeable. The force modulation experiment further proves that there is a layer coating on nanobubbles. These critical properties suggest that surface nanobubbles may be stabilized by a layer which has a great diffusive resistance.
Exergetic simulation of a combined infrared-convective drying process
NASA Astrophysics Data System (ADS)
Aghbashlo, Mortaza
2016-04-01
Optimal design and performance of a combined infrared-convective drying system with respect to the energy issue is extremely put through the application of advanced engineering analyses. This article proposes a theoretical approach for exergy analysis of the combined infrared-convective drying process using a simple heat and mass transfer model. The applicability of the developed model to actual drying processes was proved using an illustrative example for a typical food.
Enemies within: Christian Extremism, a Threat to the Homeland
2016-06-10
the time of his death, the movement vigorously developed in California, and clearly separated itself from its English roots. By the 1990s, two new...Mr. Jennings for their dedicated commitment to the development of this thesis. Your cumulative experience, knowledge and mentorship proved vital and...privileged to have developed this thesis under the tutelage of such wise leaders and thank you sincerely for a product that will serve as a changing
[Premature fetal membrane rupture: report of a case of severe intrauterine fungal infection].
Gauwerky, J; Schmidt, W; Kühn, H; Kubli, F
1983-03-01
A case of extremely rare intra-uterine candida infection is reported following premature rupture of the membranes. The diagnostic possibilities by transabdominal amniocentesis and determination of the causative organism in the amniotic fluid are presented. Even systemic antimykotic treatment is not capable of treating intra-uterine candidiasis sufficiently. This is proved among other parameters by the concentration of miconazol in the amniotic fluid and in the plasma of the newborn.
Transformation of soil organics under extreme climate events: a project description
NASA Astrophysics Data System (ADS)
Blagodatskaya, Evgenia
2017-04-01
Recent climate scenarios predict not only continued global warming but also an increased frequency and intensity of extreme climatic events such as strong changes in temperature and precipitation with unusual regional dynamics. Weather anomalies at European territory of Russia are currently revealed as long-term drought and strong showers in summer and as an increased frequency of soil freezing-thawing cycles. Climate extremes totally change biogeochemical processes and elements cycling both at the ecosystem level and at the level of soil profile mainly affecting soil biota. Misbalance in these processes can cause a reduction of soil carbon stock and an increase of greenhouse gases emission. Our project aims to reveal the transformation mechanisms of soil organic matter caused by extreme weather events taking into consideration the role of biotic-abiotic interactions in regulation of formation, maintenance and turnover of soil carbon stock. Our research strategy is based on the novel concept considering extreme climatic events (showers after long-term droughts, soil flooding, freezing-thawing) as abiotic factors initiating a microbial succession. Study on stoichiometric flexibility of plants under climate extremes as well as on resulting response of soil heterotrophs on stoichiometric changes in substrate will be used for experimental prove and further development of the theory of ecological stoichiometry. The results enable us to reveal the mechanisms of biotic - abiotic interactions responsible for the balance between mobilization and stabilization of soil organic matter. Identified mechanisms will form the basis of an ecosystem model enabled to predict the effects of extreme climatic events on biogenic carbon cycle in the biosphere.
Wilson, J D; Jones, B M; Kinghorn, G R
1988-01-01
We report the case of a woman, who baked her own bread, acquiring a vulvovaginal infection caused by saccharomyces cerevisiae, a yeast used extensively in the baking and brewing industries. Her partner was also infected, and the infections proved difficult to eradicate. Oral and topical treatment with nystatin along with disinfection of both patients' underwear produced clinical and microbiologic cure.
Unique issues raised by drug benefit design.
Berndt, Ernst R
2004-01-01
In this Perspective on the preceding paper by Joseph Newhouse, I point out a number of features of the pharmaceutical industry that differentiate it from other health care sectors. These differences help explain why it has proved to be so very difficult to construct policies that simultaneously contain health care costs, provide patients with high-quality care, and generate continued incentives for innovation. I then summarize Newhouse's preferred Medicare prescription drug benefit program and the issues it raises.
Richard Guyette; Michael Stambaugh; Daniel Dey
2011-01-01
Tree-ring dated fire scars provide long-term records of fire frequency, giving land managers valuable baseline information about the fire regimes that existed prior to Euro-American settlement. However, for the East, fire history data prove difficult to acquire because the generally moister climate of the region causes rapid decay of wood. In an endeavor to fill data...
The use of tannins in the local treatment of burn wounds - a pilot study.
Chokotho, L; van Hasselt, E
2005-06-01
Twenty patients aged 3 years and above with fresh partial thickness burns of less than 20% total body surface area were randomly assigned to local treatment of the burn wound either with a solution containing tannins (tannin group), or one of the other commonly used topical agents, such as honey and ghee, silver sulfadiazine, etc (the other group). The effects on serum transaminase and alkaline phosphatase, the incidence and type of wound infection, the quality of the eschar, the formation of scar tissue, adverse effects, the alleviation of pain and possible adverse reactions were studied in both treatment groups. Surprisingly initial assessment of the burn wound depth proved more difficult than anticipated even in the hands of the more experienced health worker. Liver function tests were elevated in both the tannin (6 patients) and the other group (7 patients). Bacterial colonization of the wounds was equally distributed in both groups, although Staphylococcus aureus was found more often in the other group (9 versus 1). The quality of the eschar was better in the tannin group (6 patients had a supple eschar versus 3 in the other group). The most important observations were that no adverse reactions were encountered and that in the tannin group only one patient developed a hypertrophic scar compared to 5 patients in the other group. It proved difficult to quantify alleviation of pain especially in the children.
Ahmed, Nauman; Hassan, Maaz Ul; Tahira, Maham; Samad, Abdul; Rana, Hamad Naeem
2018-01-01
To evaluate the intra-operative scoring system to predict difficult cholecystectomy and conversion to open surgery. This descriptive study was conducted from March 2016 to August, 2016 in the Department of Surgery, Shalimar Hospital. The study recruited 120 patients of either gender, age greater than 18 years and indicated for laparoscopic cholecystectomy (LC). Intra-operatively all patients were evaluated using the new scoring system. The scoring system included five aspects; appearance and adhesion of Gall Bladder (GB), distension or contracture degree of GB, ease in access, local or septic complications, and time required for cystic artery and duct identification. The scoring system ranges from 0 to 10, classified as score of <2 being considered easy, 2 to 4 moderate, 5-7 very difficult, and 8 to 10, extreme. Patient demographic data (i.e. age, gender), co-morbidities, intra-operative scores using the scoring system and conversion to open were recorded. The data was analysed using statistical analysis software SPSS (IBM). Among one hundred and twenty participants, sixty seven percent were females and the mean age (years) was 43.05 ± 14.16. Co-morbidities were present in twenty percent patients with eleven diagnosed with diabetes, six with hypertension and five with both hypertension and diabetes. The conversion rate to open surgery was 6.7%. The overall mean intra-operative scores were 3.52 ± 2.23; however significant difference was seen in mean operative score of converted to open and those not converted to open (8.00 ± 0.92 Vs. 3.20 V 1.92; p-value = 0.001). Among eight cases converted to open, three (37.5%) were in very difficult category while five (62.5%) were in extreme category. Moreover, age greater than 40 years and being diabetic were also the risk factors for conversion to open surgery. The new intra-operative scoring system is a valuable assessment tool to predict difficult laparoscopic cholecystectomy and conversion parameters to open surgery and its utility could improve patient's clinical outcome indicated for laparoscopic cholecystectomy.
ERIC Educational Resources Information Center
Harrison, Jason Gordon
2013-01-01
Quantum mechanical (QM) and molecular docking methods are used to probe systems of biological and synthetic interest. Probing interactions of nucleobases within proteins, and properly modeling said interactions toward novel nucleobase development, is extremely difficult, and of great utility in RNA interference (RNAi) therapeutics. The issues in…
F. Rodríguez y Silva; J.R. Molina Martínez; Armando González-Cabán
2014-01-01
Traditional uses of the forest (timber, forage) have been giving way to other uses more in demand (recreation, ecosystem services). An observable consequence of this process of forest land use conversion is an increase in more difficult and extreme wildfires. Wildland forest management and protection program budgets are limited, and managers are requesting help in...
Hurricane impacts on forest resources in the Eastern United States: a post-sandy assessment
Greg C. Liknes; Susan J. Crocker; Randall S. Morin; Brian F. Walters
2015-01-01
Extreme weather events play a role in shaping the composition and structure of forests. Responding to and mitigating a storm event in a forested environment requires information about the location and severity of tree damage. However, this information can be difficult to obtain immediately following an event. Post-storm assessments using regularly collected forest...
Dynamics of cracks in disordered materials
NASA Astrophysics Data System (ADS)
Bonamy, Daniel
2017-05-01
Predicting when rupture occurs or cracks progress is a major challenge in numerous fields of industrial, societal, and geophysical importance. It remains largely unsolved: stress enhancement at cracks and defects, indeed, makes the macroscale dynamics extremely sensitive to the microscale material disorder. This results in giant statistical fluctuations and non-trivial behaviors upon upscaling, difficult to assess via the continuum approaches of engineering.
Tibetan-English Dictionary of Modern Tibetan. Bibliotheca Himalayica, Series II, Vol. 9.
ERIC Educational Resources Information Center
Goldstein, Melvyn C., Ed.
Recent political events have triggered a revolution in the Tibetan language. The entrance of Tibet into the world arena of politics, science and technology has led to the creation of thousands of new lexical items in a relatively short period of time. Because of these changes, modern literary Tibetan is extremely difficult for non-Tibetans to…
USDA-ARS?s Scientific Manuscript database
Immunoassays contribute greatly to veterinary drug residue analysis and food safety, but there are no reported immunoassays on simultaneously detecting MQCA and QCA, the marker residues for carbadox and olaquindox. It is extremely difficult to produce broad-specificity antibodies that bind both res...
Integrated Spacesuit Audio System Enhances Speech Quality and Reduces Noise
NASA Technical Reports Server (NTRS)
Huang, Yiteng Arden; Chen, Jingdong; Chen, Shaoyan Sharyl
2009-01-01
A new approach has been proposed for increasing astronaut comfort and speech capture. Currently, the special design of a spacesuit forms an extreme acoustic environment making it difficult to capture clear speech without compromising comfort. The proposed Integrated Spacesuit Audio (ISA) system is to incorporate the microphones into the helmet and use software to extract voice signals from background noise.
USDA-ARS?s Scientific Manuscript database
The emerald ash borer, Agrilus planipennis Fairmaire, an invasive beetle from Asia causing large scale ash (Fraxinus spp.) mortality in North America, has been extremely difficult to rear in the laboratory because of its long life cycle and cryptic nature of immature stages. This lack of effective ...
ERIC Educational Resources Information Center
Dahl, Robyn Mieko; Droser, Mary L.
2016-01-01
University earth science departments seeking to establish meaningful geoscience outreach programs often pursue large-scale, grant-funded programs. Although this type of outreach is highly successful, it is also extremely costly, and grant funding can be difficult to secure. Here, we present the Geoscience Education Outreach Program (GEOP), a…
2007-08-02
Societal stigmas against gangs and gang- deportees from the United States have made the process of leaving a gang extremely difficult. A recent...often unwilling to hire them. Tattooed former gang members, especially returning deportees from the United States who are often native English...recipients of deportees on a per capita basis. For all Central American countries, with the exception of Panama, those deported on criminal grounds
Michelle F. Tacconelli; Edward F. Loewenstein
2012-01-01
Natural resource managers must often balance multiple objectives on a single property. When these objectives are seemingly conflicting, the managerâs job can be extremely difficult and complex. This paper presents a decision support tool, designed to aid land managers in optimizing wildlife habitat needs while accomplishing additional objectives such as ecosystem...
Relevance of antarctic microbial ecosystems to exobiology
NASA Technical Reports Server (NTRS)
Mckay, Christopher P.
1993-01-01
Antarctic microbial ecosystems which provide biological and physical analogs that can be used in exobiology are studied. Since the access to extraterrestrial habitats is extremely difficult, terrestrial analogs represent the best opportunity for both formulation and preliminary testing of hypothesis about life. Antarctica, as one of few suitable environments on earth is considered to be a major locus of progress in exobiology.
ERIC Educational Resources Information Center
Rajulton, Fernando; Ravanera, Zenaida R.; Beaujot, Roderic
2007-01-01
Social cohesion is a concept difficult to define and to measure. As there can be many definitions, so there can be many measurements. The main problem, either in defining or measuring the concept, is its multilevel and multidimensional nature. At one extreme, "country" is the most commonly used level to view social cohesion but…
ERIC Educational Resources Information Center
Reyes Paulino, Lisette G.
2012-01-01
An epidemic such as diabetes is an extremely complex public health, economic and social problem that is difficult to solve through medical expertise alone. Evidence-based models for improving healthcare delivery systems advocate educating patients to become more active participants in their own care. This shift demands preparing chronically ill…
Heterotopic Prostate at Autopsy- An Unusual Mass at the Dome of the Urinary Bladder
Munde, Shital; Phadnis, Priyanka
2017-01-01
Heterotopic prostate in the dome of the urinary bladder is extremely rare and difficult to diagnose. It is often mistaken for neoplastic masses and histopathological examination is warranted for diagnosis. We report an autopsy case of an ectopic prostate at the dome of the bladder which mimicked a neoplasm on gross pathology. PMID:29207717
Investigating the Stability of Benzoyl Peroxide in Over-the-Counter Acne Medications
ERIC Educational Resources Information Center
Kittredge, Marina Canepa; Kittredge, Kevin W.; Sokol, Melissa S.; Sarquis, Arlyne M.; Sennet, Laura M.
2008-01-01
One of the most commonly used ingredients in over-the-counter acne treatments in cream, gel, and wash form is benzoyl peroxide. It is an anti-bacterial agent that kills the bacterium ("Propionibacterium acne") involved in the formation of acne. The formulation of these products is extremely difficult owing to the instability of benzoyl peroxide.…
ERIC Educational Resources Information Center
Adduci, Stacy B.
2017-01-01
Improving the nation's math prowess and preparing the youth to be college or career ready, may need to be solved by a culmination of theories from different perspectives. As the controversial meshing hypothesis contends that teachers should present information according to each students' learning styles; this can be extremely difficult in a…
Influence of sleep deprivation and auditory intensity on reaction time and response force.
Włodarczyk, Dariusz; Jaśkowski, Piotr; Nowik, Agnieszka
2002-06-01
Arousal and activation are two variables supposed to underlie change in response force. This study was undertaken to explain these roles, specifically, for strong auditory stimuli and sleep deficit. Loud auditory stimuli can evoke phasic overarousal whereas sleep deficit leads to general underarousal. Moreover, Van der Molen and Keuss (1979, 1981) showed that paradoxically long reaction times occurred with extremely strong auditory stimuli when the task was difficult, e.g., choice reaction or Simon paradigm. It was argued that this paradoxical behavior related to reaction time is due to active disconnecting of the coupling between arousal and activation to prevent false responses. If so, we predicted that for extremely loud stimuli and for difficult tasks, the lengthening of reaction time should be associated with reduction of response force. The effects of loudness and sleep deficit on response time and force were investigated in three different tasks: simple response, choice response, and Simon paradigm. According to our expectation, we found a detrimental effect of sleep deficit on reaction time and on response force. In contrast to Van der Molen and Keuss, we found no increase in reaction time for loud stimuli (up to 110 dB) even on the Simon task.
Application of a fast skyline computation algorithm for serendipitous searching problems
NASA Astrophysics Data System (ADS)
Koizumi, Kenichi; Hiraki, Kei; Inaba, Mary
2018-02-01
Skyline computation is a method of extracting interesting entries from a large population with multiple attributes. These entries, called skyline or Pareto optimal entries, are known to have extreme characteristics that cannot be found by outlier detection methods. Skyline computation is an important task for characterizing large amounts of data and selecting interesting entries with extreme features. When the population changes dynamically, the task of calculating a sequence of skyline sets is called continuous skyline computation. This task is known to be difficult to perform for the following reasons: (1) information of non-skyline entries must be stored since they may join the skyline in the future; (2) the appearance or disappearance of even a single entry can change the skyline drastically; (3) it is difficult to adopt a geometric acceleration algorithm for skyline computation tasks with high-dimensional datasets. Our new algorithm called jointed rooted-tree (JR-tree) manages entries using a rooted tree structure. JR-tree delays extend the tree to deep levels to accelerate tree construction and traversal. In this study, we presented the difficulties in extracting entries tagged with a rare label in high-dimensional space and the potential of fast skyline computation in low-latency cell identification technology.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Lusk, Ewing; Butler, Ralph; Pieper, Steven C.
Here, we take a historical approach to our presentation of self-scheduled task parallelism, a programming model with its origins in early irregular and nondeterministic computations encountered in automated theorem proving and logic programming. We show how an extremely simple task model has evolved into a system, asynchronous dynamic load balancing (ADLB), and a scalable implementation capable of supporting sophisticated applications on today’s (and tomorrow’s) largest supercomputers; and we illustrate the use of ADLB with a Green’s function Monte Carlo application, a modern, mature nuclear physics code in production use. Our lesson is that by surrendering a certain amount of generalitymore » and thus applicability, a minimal programming model (in terms of its basic concepts and the size of its application programmer interface) can achieve extreme scalability without introducing complexity.« less
Extreme Rock Distributions on Mars and Implications for Landing Safety
NASA Technical Reports Server (NTRS)
Golombek, M. P.
2001-01-01
Prior to the landing of Mars Pathfinder, the size-frequency distribution of rocks from the two Viking landing sites and Earth analog surfaces was used to derive a size-frequency model, for nomimal rock distributions on Mars. This work, coupled with extensive testing of the Pathfinder airbag landing system, allowed an estimate of what total rock abundances derived from thermal differencing techniques could be considered safe for landing. Predictions based on this model proved largely correct at predicting the size-frequency distribution of rocks at the Mars Pathfinder site and the fraction of potentially hazardous rocks. In this abstract, extreme rock distributions observed in Mars Orbiter Camera (MOC) images are compared with those observed at the three landing sites and model distributions as an additional constraint on potentially hazardous surfaces on Mars.
Forensic Analysis of Windows Hosts Using UNIX-based Tools
DOE Office of Scientific and Technical Information (OSTI.GOV)
Cory Altheide
2004-07-19
Many forensic examiners are introduced to UNIX-based forensic utilities when faced with investigating a UNIX-like operating system for the first time. They will use these utilities for this very specific task, because in many cases these tools are the only ones for the given job. For example, at the time of this writing, given a FreeBSD 5.x file system, the author's only choice is to use The Coroner's Toolkit running on FreeBSD 5.x. However, many of the same tools examiners use for the occasional UNIX-like system investigation are extremely capable when a Windows system is the target. Indeed, the Linuxmore » operating system itself can prove to be an extremely useful forensics platform with very little use of specialized forensics utilities at all.« less
NASA Astrophysics Data System (ADS)
Hod, Shahar
2018-05-01
The quasinormal resonant modes of massless neutral fields in near-extremal Kerr-Newman-de Sitter black-hole spacetimes are calculated in the eikonal regime. It is explicitly proved that, in the angular momentum regime a bar >√{1 - 2 Λ bar/4 + Λ bar / 3 }, the black-hole spacetimes are characterized by slowly decaying resonant modes which are described by the compact formula ℑ ω (n) =κ+ ṡ (n + 1/2 ) [here the physical parameters { a bar ,κ+ , Λ bar , n } are respectively the dimensionless angular momentum of the black hole, its characteristic surface gravity, the dimensionless cosmological constant of the spacetime, and the integer resonance parameter]. Our results support the validity of the Penrose strong cosmic censorship conjecture in these black-hole spacetimes.
DOE Office of Scientific and Technical Information (OSTI.GOV)
Guo Xiaoming
The dominated process of controlled fusion is to let nuclei gain enough kinetic energy to overcome Coulomb barrier. As a result, a fusion scheme can consider two factors in its design: to increase kinetic energy of nuclei and to alter the Coulomb barrier. Cold Fusion and Hot fusion are all one-factor schemes while Intermediate Fusion is a twofactors scheme. This made CINF kinetically superior. Cold Fusion reduces deuteron-deuteron distance, addressing Coulomb barrier, and Hot Fusion heat up plasma into extreme high temperature, addressing kinetic energy. Without enough kinetic energy made Cold Fusion skeptical. Extreme high temperature made Hot Fusion verymore » difficult to engineer. Because CIFN addresses both factors, CIFN is a more promising technique to be industrialized.« less
Complexity-aware simple modeling.
Gómez-Schiavon, Mariana; El-Samad, Hana
2018-02-26
Mathematical models continue to be essential for deepening our understanding of biology. On one extreme, simple or small-scale models help delineate general biological principles. However, the parsimony of detail in these models as well as their assumption of modularity and insulation make them inaccurate for describing quantitative features. On the other extreme, large-scale and detailed models can quantitatively recapitulate a phenotype of interest, but have to rely on many unknown parameters, making them often difficult to parse mechanistically and to use for extracting general principles. We discuss some examples of a new approach-complexity-aware simple modeling-that can bridge the gap between the small-scale and large-scale approaches. Copyright © 2018 Elsevier Ltd. All rights reserved.
Kinetic advantage of controlled intermediate nuclear fusion
NASA Astrophysics Data System (ADS)
Guo, Xiaoming
2012-09-01
The dominated process of controlled fusion is to let nuclei gain enough kinetic energy to overcome Coulomb barrier. As a result, a fusion scheme can consider two factors in its design: to increase kinetic energy of nuclei and to alter the Coulomb barrier. Cold Fusion and Hot fusion are all one-factor schemes while Intermediate Fusion is a twofactors scheme. This made CINF kinetically superior. Cold Fusion reduces deuteron-deuteron distance, addressing Coulomb barrier, and Hot Fusion heat up plasma into extreme high temperature, addressing kinetic energy. Without enough kinetic energy made Cold Fusion skeptical. Extreme high temperature made Hot Fusion very difficult to engineer. Because CIFN addresses both factors, CIFN is a more promising technique to be industrialized.
Chamilos, Georgios; Kontoyiannis, Dimitrios P
2006-08-01
Despite expansion of the antifungal armamentarium over the past decade, the mortality rate for invasive fungal infections remains high in severely immunocompromised patients. Furthermore, in recent years, difficult-to-treat invasive infections caused by rare molds and yeasts have emerged in high-risk patients receiving antifungal prophylaxis or empirical treatment. Antifungal combinations are increasingly used in clinical practice to improve outcomes for refractory mycoses because of the suboptimal efficacy of current antifungal agents. Herein we review recent advances in the area of antifungal combinations in high-risk patients to separate empiricism from evidence-based medicine. Thus far, the benefits of combination antifungal therapy have been difficult to prove for invasive fungal infections other than cryptococcal meningitis. The recent introduction of a new class of antifungal agents (the echinocandins) and extended-spectrum triazoles has rejuvenated interest in studying those combinations for difficult-to-treat aspergillosis, as recent observational studies show promise. In view of the evolving epidemiology of invasive fungal infections, combination antifungal therapy could be most valuable in preemptive management of carefully selected high-risk patients; however, this should be studied in appropriate trials.
Clinicians' recognition and management of emotions during difficult healthcare conversations.
Martin, Elliott B; Mazzola, Natalia M; Brandano, Jessica; Luff, Donna; Zurakowski, David; Meyer, Elaine C
2015-10-01
To examine the most commonly reported emotions encountered among healthcare practitioners when holding difficult conversations, including frequency and impact on care delivery. Interprofessional learners from a range of experience levels and specialties completed self-report questionnaires prior to simulation-based communication workshops. Clinicians were asked to describe up to three emotions they experienced when having difficult healthcare conversations; subsequent questions used Likert-scales to measure frequency of each emotion, and whether care was affected. 152 participants completed questionnaires, including physicians, nurses, and psychosocial professionals. Most commonly reported emotions were anxiety, sadness, empathy, frustration, and insecurity. There were significant differences in how clinicians perceived these different emotions affecting care. Empathy and anxiety were emotions perceived to influence care more than sadness, frustration, and insecurity. Most clinicians, regardless of clinical experience and discipline, find their emotional state influences the quality of their care delivery. Most clinicians rate themselves as somewhat to quite capable of recognizing and managing their emotions, acknowledging significant room to grow. Further education designed to increase clinicians' recognition of, reflection on, and management of emotion would likely prove helpful in improving their ability to navigate difficult healthcare conversations. Interventions aimed at anxiety management are particularly needed. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.
Germanakis, Antonis; Chochlakis, Dimosthenis; Angelakis, Emmanouil; Tselentis, Yannis; Psaroulaki, Anna
2014-01-01
The main clinical signs and symptoms caused by a rickettsial infection typically begin 6-10 days after the bite and are accompanied by nonspecific findings such as fever, headache and muscle pain. The diagnosis is mainly based on serological tests, however antibody presentation may be delayed, at least at the early stages of the disease, while seroconversion is usually detected 10-15 days after disease onset. Culture is difficult, requires optimized facilities and often proves negative. Under this scope, the presence of a characteristic inoculation eschar at the bite site may prove a useful clinical tool towards the early suspicion and diagnosis/differential diagnosis of tick-borne rickettsioses, even before the onset of rash and fever or serological confirmation. We describe herein the presence of skin lesions and/or an inoculation eschar at the tick bite site in 17 patients diagnosed, by molecular means, as suffering from spotted fever group rickettsioses. The detection of the pathogen's DNA in biopsy samples proved to be a useful means for early rickettsiae detection and identification. Moreover, the presence of an infiltrated erythema always seemed to precede the appearance of an eschar by 2-5 days and the initiation of fever by 1-10 days; these two signs might also prove useful in the context of the final diagnosis. © 2014 S. Karger AG, Basel.
Surface Analysis Evaluation of Handwipe Cleaning for the Space Shuttle RSRM
NASA Technical Reports Server (NTRS)
Lesley, Michael W.; Anderson, Erin L.; McCool, Alex (Technical Monitor)
2001-01-01
In this paper we discuss the role of surface-sensitive spectroscopy (electron spectroscopy for chemical analysis, or ESCA) in the selection of solvents to replace 1,1,1-trichloroethane in handwipe cleaning of bonding surfaces on NASA's Space Shuttle Reusable Solid Rocket Motor (RSRM). Removal of common process soils from a wide variety of metallic and polymeric substrates was characterized. The cleaning efficiency was usually more dependent on the type of substrate being cleaned and the specific process soil than on the solvent used. A few substrates that are microscopically rough or porous proved to be difficult to clean with any cleaner, and some soils were very tenacious and difficult to remove from any substrate below detection limits. Overall, the work showed that a wide variety of solvents will perform at least as well as 1,1,1-trichloroethane.
Electric Fields and Enzyme Catalysis
Fried, Stephen D.; Boxer, Steven G.
2017-01-01
What happens inside an enzyme’s active site to allow slow and difficult chemical reactions to occur so rapidly? This question has occupied biochemists’ attention for a long time. Computer models of increasing sophistication have predicted an important role for electrostatic interactions in enzymatic reactions, yet this hypothesis has proved vexingly difficult to test experimentally. Recent experiments utilizing the vibrational Stark effect make it possible to measure the electric field a substrate molecule experiences when bound inside its enzyme’s active site. These experiments have provided compelling evidence supporting a major electrostatic contribution to enzymatic catalysis. Here, we review these results and develop a simple model for electrostatic catalysis that enables us to incorporate disparate concepts introduced by many investigators to describe how enzymes work into a more unified framework stressing the importance of electric fields at the active site. PMID:28375745
Holländer, R; Ebke, M; Barck, H; von Pritzbuer, E
2001-07-01
During 11 months 58 extended-spectrum beta-lactamase-producing Klebsiella pneumoniae (ESBL-Kp) isolates were grown from 10 patients on a neurological early rehabilitation unit. The patients had no signs of infection but were colonized in the nose and trachea, and unusually only one had colonization in the gut. A single clone of ESBL-Kp was identified by pulse field gel electrophoresis. Strong hygienic precautions similar to those for Methicillin-resistant Staphylococcus aureus patients prevented spread of the bacteria to other wards. However, rehabilitation for patients with severe neurological failures made it very difficult to follow hygienic requirements. Disinfection of mucous membranes was difficult. Eventually the application of a nasal spray containing povidone-iodine proved to be successful. Copyright 2001 The Hospital Infection Society.
One-per-mil tumescent technique for upper extremity surgeries: broadening the indication.
Prasetyono, Theddeus O H; Biben, Johannes A
2014-01-01
We studied the effect of 1:1,000,000 epinephrine concentration (1 per mil) to attain a bloodless operative field in hand and upper extremity surgery and to explore its effectiveness and safety profile. This retrospective observational study enrolled 45 consecutive patients with 63 operative fields consisting of various hand and upper extremity problems. One-per-mil solution was injected into the operative field with tumescent technique to create a bloodless operating field without tourniquet. The solution was formulated by adding a 1:1,000,000 concentration of epinephrine and 100 mg of lidocaine into saline solution to form 50 mL of tumescent solution. Observation was performed on the clarity of the operative field, which we described as totally bloodless, minimal bleeding, acceptable bleeding, or bloody. The volume of tumescent solution injected, duration of surgery, and surgical outcome were also reviewed. The tumescent technique with 1-per-mil solution achieved 29% totally bloodless, 48% minimal bleeding, 22% acceptable bleeding, and 2% bloody operative fields in cases that included burn contracture and congenital hand and upper extremity surgeries. One-per-mil tumescent solution created a clear operative field in hand and upper extremity surgery. It proved safe and effective for a wide range of indications. Therapeutic IV. Copyright © 2014 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.
Jensen, Philip J; Fazio, Gennaro; Altman, Naomi; Praul, Craig; McNellis, Timothy W
2014-04-04
Apple tree breeding is slow and difficult due to long generation times, self-incompatibility, and complex genetics. The identification of molecular markers linked to traits of interest is a way to expedite the breeding process. In the present study, we aimed to identify genes whose steady-state transcript abundance was associated with inheritance of specific traits segregating in an apple (Malus × domestica) rootstock F1 breeding population, including resistance to powdery mildew (Podosphaera leucotricha) disease and woolly apple aphid (Eriosoma lanigerum). Transcription profiling was performed for 48 individual F1 apple trees from a cross of two highly heterozygous parents, using RNA isolated from healthy, actively-growing shoot tips and a custom apple DNA oligonucleotide microarray representing 26,000 unique transcripts. Genome-wide expression profiles were not clear indicators of powdery mildew or woolly apple aphid resistance phenotype. However, standard differential gene expression analysis between phenotypic groups of trees revealed relatively small sets of genes with trait-associated expression levels. For example, thirty genes were identified that were differentially expressed between trees resistant and susceptible to powdery mildew. Interestingly, the genes encoding twenty-four of these transcripts were physically clustered on chromosome 12. Similarly, seven genes were identified that were differentially expressed between trees resistant and susceptible to woolly apple aphid, and the genes encoding five of these transcripts were also clustered, this time on chromosome 17. In each case, the gene clusters were in the vicinity of previously identified major quantitative trait loci for the corresponding trait. Similar results were obtained for a series of molecular traits. Several of the differentially expressed genes were used to develop DNA polymorphism markers linked to powdery mildew disease and woolly apple aphid resistance. Gene expression profiling and trait-associated transcript analysis using an apple F1 population readily identified genes physically linked to powdery mildew disease resistance and woolly apple aphid resistance loci. This result was especially useful in apple, where extreme levels of heterozygosity make the development of reliable DNA markers quite difficult. The results suggest that this approach could prove effective in crops with complicated genetics, or for which few genomic information resources are available.
The return of international labour migrants in the ESCAP Region.
1986-03-01
The social phenomenon of massive temporary international labor migration from the ESCAP region has emerged extremely rapidly. Within 10 years, the number of persons from ESCAP countries grew from a negligible one to 3.5 million. Related research and government policies have lagged behind this latest surge in migration. Most research conducted has been small-scale and lacks an analytical or theoretical framework. Policy formulation for temporary labor migration is difficult because most of the rapid growth in the industry has occurred as a result of private efforts, with a minimum of government intervention. It is now difficult, for the government to provide effective regulations or measures to stimulate and assist the process. Regulations on compulsory remittances or overseas minimum wages have proved to be unrealistic and, if not rescinded, are routinely circumvented. The most effective policies to assist return migrants may not be those which are intended to do so, but those which control the earlier stages of the migration process, such as recruitment, working conditions, and banking arrangements. The most valuable policies may also include those affecting education, training, employment, and general socioeconomic growth. Governments are recommended to provide social services for migrants and their families who are experiencing problems, and to institute community programs in areas with a large number of labor migrants. Governmental efforts to promote forms of labor migration beneficial to the workers would be valuable and should include measures to identify overseas labor markets for employing its nationals, government ot government labor contracts, and government participation in joint-venture projects. International migration should be analyzed in the context of theories and social change in order for governments to formulate effective measures for the reintegration of returning workers. Labor migration on the current scale has many social implications for the sending countries; relationships between employers and employees, the government and private sectors, and white and blue collar workers are affected. Social change and technological innovation will become more rapid, women's status and family roles will change markedly, and behavior is likely to become less conformist and more individualistic.
NASA Astrophysics Data System (ADS)
Anderson, C.
2017-12-01
California's hydroclimatic regime is characterized by extreme interannual variability including periodic, multi-year droughts and winter flooding sequences. Statewide, water years 2012-2016 were characterized by extreme drought followed by likely one of the wettest years on record in water year 2017. Similar drought-flood patterns have occurred multiple times both in the contemporary empirical record and reconstructed climate records. Both the extreme magnitude and rapid succession of these hydroclimatic periods pose difficult challenges for water managers and regulatory agencies responsible for providing instream flows to protect and recover threatened and endangered fish species. Principal among these riverine fish species are federally listed winter-run and spring-run Chinook salmon (Oncorhynchus tshawytscha), Central Valley steelhead (Oncorhynchus mykiss), and the pelagic species Delta smelt (Hypomesus transpacificus). Poor instream conditions from 2012-2016 resulted in extremely low abundance estimates and poor overall fish health, and while fish monitoring results from water year 2017 are too preliminary to draw substantive conclusions, early indicators show continued downward population trends despite the historically wet conditions. This poster evaluates California's hydroclimatic conditions over the past decade and quantifies resultant impacts of the 2012-2016 drought and the extremely wet 2017 water year to both adult escapement and juvenile production estimates in California's major inland salmon rivers over that same time span. We will also examine local, state, and federal regulatory actions both in response to the extreme hydroclimatic variability and in preparation for future drought-flood sequences.
[Mortality in Nuremberg in the 19th century (about 1800 to 1913)].
Vasold, Manfred
2006-01-01
Before the middle of the 19th century urban life was hazardous, life expectancy in big cities was shorter than in the countryside, it was half as high as it is today. Cities used to be called "the graves of mankind"; they were unhygienic, since their inhabitants lived under crowded, unhealthy conditions. In German cities infant mortality was extremely high, one out of three new-born children died within its first year. In most big cities more people died in any given year than were born. In 1806, when the Imperial City of Nuremberg was absorbed by the Kingdom of Bavaria, it had 25 000 inhabitants, fewer than around the year 1600. In the following decades Nuremberg grew quickly, up to 50000 in 1846 and 100000 in 1881, 330000 in 1910. Its population was living extremely crowded within the medieval city-walls, up to 58 000 (1885) in the old parts of the city, more than twice as many as in 1806. Mortality was bound to increase, as more and more people moved to Nuremberg. Mortality rose from 25.5 per thousand in the 1820's to 29.4 in the 1850's and 32.8 in the 1860's. This increase of population was mainly due to migration from outside, from the countryside. New industries settled down in Nuremberg and provided new jobs, the new factories produced lots of smoke and dangerous dust. The general living conditions of the workers were poor, people were much smaller than nowadays. During the industrialisation labor was backbreaking, working hours were extremely long, and annual working hours were more than twice as long as today. New and better legislation was written by the Northern German Confederation, founded in 1867. Now the magistrate of Nuremberg recognised that something had to be done. In the following years physicians began to collect information as to morbidity and mortality in various parts of Nuremberg. Very many people still died of infectious diseases, esp. of tubercolosis, typhoid fever, diphtheria, pertussis, scarlet fever and other infectious diseases. There were many cases of bronchitis and deadly pneumonia. Even suicide was an important cause of death. In 1886 mortality at Nuremberg peaked for the last time above 30. Nuremberg had fewer doctors than other big cities in Germany. The city-fathers noticed that the public wells and the drinking water were dirty--they were getting more and more contaminated as time went by. It proved extremely difficult to provide this fast growing population with "free goods" like clean water and air. In the 1870's Nuremberg began to build a new water supply and a modern municipal sewer system. Cases of typhoid fever declined quickly thereafter. The magistrate did not provide new apartment-houses, but it took care that the new houses were more hygienic, with toilets and other necessary facilities. After 1880 new vaccinations were developed by modern medicine, these and other methods of preventive medicin proved to be more important for prolonging human lifes than therapeutic medicine. In the 1880's a steep rise of income can be registered, it brought more and better food, more meat, and better living and working conditions--and fewer working-hours per year. At the eve of World War I, Nuremberg was one of the ten or twelve biggest cities in Germany, an industrialized city with a hard-working population, people with little education and income. Urban mortality in Nuremberg declined rather slowly. In 1867 35.7 percent of all deceased persons were infants, less than one year old, in 1913 that percentage had declined to 30.7. In 1867 only 9.3 per cent of the deceased were older than 70, in 1913 the elderly constituted 14.2 per cent. Very many people still died in their forties or fifties.
Entropy of black holes in N=2 supergravity
NASA Astrophysics Data System (ADS)
Chatterjee, A.
2018-07-01
Using the formalism of isolated horizons, we construct space of solutions of asymptotically flat extremal black holes in N=2 pure supergravity in 4 dimensions. We prove that the laws of black hole mechanics hold for these black holes. Further, restricting to constant area phase space, we show that the spherical horizons admit a Chern-Simons theory. Standard way of quantizing this topological theory and counting states confirms that entropy is indeed proportional to the area of horizon.
Diagnosis and treatment of academic frustration syndrome.
Grover, P L; Tessier, K E
1978-09-01
A random sample of medical students was compared with others who were unable to cope with unanticipated academic frustration. The noncoping students demonstrated higher levels of debilitating anxiety and lower levels of facilitating anxiety while their perceptions of locus of control tended to be more extreme. No difference was found in study habits and attitudes. Techniques of attribution therapy and desensitization in the counseling of these students proved to be effective in improving coping behavior in six of seven cases.
The Army of Zimbabwe: A Role Model for Namibia
1990-03-02
centuries. A limited sense of nationhood started to exist. Further south on the African continent Zulu dissidents broke from the main empire and in...important role. 13 One of the manifestations of this unity would emerge in the creation of the new Zimbabwe Defense Forces. 6 ENDNOTES 1. DA PAM 550-171...prove to be very helpful in the months to come, 25 as BMATT arrived, set up, came on line and started its difficult mission. The creation of the first
Basal cell carcinomas in elderly patients treated by cryotherapy
Chiriac, Anca; Mihaila, Doina; Foia, Liliana; Solovan, Caius
2013-01-01
Basal cell carcinoma is a malignant skin tumor with high incidence in our country, especially in rural areas, on sun-exposed skin (particularly on the face) in elderly patients. We present three cases of basal cell carcinoma with good results with cryotherapy. This report aims to outline and to prove that in some difficult situations, a simple, inexpensive, easy-to-perform procedure with no contraindications and with minimal side effects (erythema, mild pain) can be applied and resolve such cases. PMID:23569366
[Lead poisoning: towards a paleo-epidemiologic re-interpretation?].
Bourdieu, Anne
2014-01-01
Lead is a major public health issue. Its use has been increasing since Neolithic times, climaxing in the Ancient Rome and the nineteenth century. Defining the frequency of plumbism before modern times proves to be a difficult matter because of its various and delayed symptoms, and of diagenetic processes affecting bones. After reviewing various methods of lead measurement in bone and tooth, we will expose ways to ascertain lead measurement interpretation in order to estimate the epidemiology of plumbism in ancient times.
A New Tool for Effective and Efficient Project Management
DOE Office of Scientific and Technical Information (OSTI.GOV)
Willett, Jesse A
2011-12-01
Organizations routinely handle thousands of projects per year, and it is difficult to manage all these projects concurrently. Too often, projects do not get the attention they need when they need it. Management inattention can lead to late projects or projects with less than desirable content and/or deliverables. This paper discusses the application of Visual Project Management (VPM) as a method to track and manage projects. The VPM approach proved to be a powerful management tool without the overhead and restrictions of traditional management methods.
A digital memories based user authentication scheme with privacy preservation.
Liu, JunLiang; Lyu, Qiuyun; Wang, Qiuhua; Yu, Xiangxiang
2017-01-01
The traditional username/password or PIN based authentication scheme, which still remains the most popular form of authentication, has been proved insecure, unmemorable and vulnerable to guessing, dictionary attack, key-logger, shoulder-surfing and social engineering. Based on this, a large number of new alternative methods have recently been proposed. However, most of them rely on users being able to accurately recall complex and unmemorable information or using extra hardware (such as a USB Key), which makes authentication more difficult and confusing. In this paper, we propose a Digital Memories based user authentication scheme adopting homomorphic encryption and a public key encryption design which can protect users' privacy effectively, prevent tracking and provide multi-level security in an Internet & IoT environment. Also, we prove the superior reliability and security of our scheme compared to other schemes and present a performance analysis and promising evaluation results.
Satellite techniques yield insight into devastating rainfall from Hurricane Mitch
NASA Astrophysics Data System (ADS)
Ferraro, R.; Vicente, G.; Ba, M.; Gruber, A.; Scofield, R.; Li, Q.; Weldon, R.
Hurricane Mitch may prove to be one of the most devastating tropical cyclones to affect the western hemisphere. Heavy rains over Central America from October 28, 1998, to November 1, 1998, caused widespread flooding and mud slides in Nicaragua and Honduras resulting in thousands of deaths and missing persons. News reports indicated entire towns being swept away, destruction of national economies and infrastructure, and widespread disease in the aftermath of the storm, which some estimates suggested dropped as much as 1300 mm of rain.However, in view of the widespread damage it is difficult to determine the actual amounts and distribution of rainfall. More accurate means of determining the rainfall associated with Mitch are vital for diagnosing and understanding the evolution of this disaster and for developing new mitigation strategies for future tropical cyclones. Satellite data may prove to be a reliable resource for accurate rainfall analysis and have yielded apparently reliable figures for Hurricane Mitch.
A digital memories based user authentication scheme with privacy preservation
Liu, JunLiang; Lyu, Qiuyun; Wang, Qiuhua; Yu, Xiangxiang
2017-01-01
The traditional username/password or PIN based authentication scheme, which still remains the most popular form of authentication, has been proved insecure, unmemorable and vulnerable to guessing, dictionary attack, key-logger, shoulder-surfing and social engineering. Based on this, a large number of new alternative methods have recently been proposed. However, most of them rely on users being able to accurately recall complex and unmemorable information or using extra hardware (such as a USB Key), which makes authentication more difficult and confusing. In this paper, we propose a Digital Memories based user authentication scheme adopting homomorphic encryption and a public key encryption design which can protect users’ privacy effectively, prevent tracking and provide multi-level security in an Internet & IoT environment. Also, we prove the superior reliability and security of our scheme compared to other schemes and present a performance analysis and promising evaluation results. PMID:29190659
The administrator's quest for quality.
Ross, A
1988-01-01
Times are tough and will become even tougher. Retrenchment issues will be foremost in many operational settings. Failure to understand baseline quality standards will make it extremely difficult to know where to cut and how to regroup without adversely affecting patient attitudes and service. Practice patterns are changing rapidly and the astute administrator needs to be prepared to participate freely in decisions affecting quality, service and costs.
Labor Market Changes in the Next Ten Years. Issue Paper No. 4.
ERIC Educational Resources Information Center
Barnow, Burt S.
Although projecting what the labor market will be like in 10 years is extremely difficult, it is useful to consider what is in store for the nation in terms of employment. In 1985, the civilian labor force of the United States averaged 115 million persons, with 8 million (7.2 percent) unemployed. Unemployment was much higher for young people and…
Cleft Lip and Cleft Palate--What to Know and Who Can Help
ERIC Educational Resources Information Center
Apel, Laura
2008-01-01
Craniofacial defects such as cleft lip and cleft palate are among the most common of all birth defects in the United States, with one in every 600 newborns affected. Cleft lip and/or palate can occur as an isolated condition or may be one component of an inherited disease or syndrome. Dealing with the condition is an extremely difficult and…
The Devil Is in the Details: Key Questions in the Effort To "End Welfare as We Know It."
ERIC Educational Resources Information Center
Greenberg, Mark
Noting the while there may be much support for the principle that families on welfare should have access to 2 years of education and training and then be expected to work, this paper contends that it will be extremely difficult, perhaps impossible, to design a coherent and constructive program within the probable federal budget constraints. In…
Industry Studies 2004: Biotechnology
2004-01-01
for biological agent research, development, and production are available on the open market. Since biological weapons are relatively cheap, easy to...growing concern is that non-state actors will acquire and use a biological weapon , the “poor man’s nuclear weapon .” Such action is extremely difficult...to detect and counter. International Protocols and the Need to Control Agents and Technologies - The Biological and Toxin Weapons Convention
1990-09-01
increasing 2 complexity of Air Force weapon systems makes the estimation of LCC an extremely difficult task. To accomplish this, mathematical models are...maintenance is nearly horizontal. A reduction in this rate from 2.8 to 2.6 (approx. 7%j resulted in cost savings of around 0.1% for the three lvel concept. The
JPRS Report, Soviet Union, Political Affairs
1988-10-26
Christa Wolfs novel "Patterns of Childhood." This very sensitive and timely work reflects the psychology attending the rise of fascism. We also have...incriminating evidence and extenuating circumstances? Psychologically , it is extremely difficult. There are allegations, there are sus- picions, there are...Zionism, which has for a long time been chipping away at the socialist foundation of our society, with its perfidious psychological methods." What does
2008-03-27
deportees from the United States have made the process of leaving a gang extremely difficult. A recent State Department report on youth gangs in El...gang members, especially returning deportees from the United States who are often native English speakers, have had the most difficulty finding...with the exception of Panama, have a much lower percentage of criminal deportees than the regional average of 39%. For example, criminal deportees
Sine Qua Non: Indispensable Resources for Ed Tech Professionals. Part 1: Educational Technology
ERIC Educational Resources Information Center
Conley, Kate
2004-01-01
Because the field of educational technology is so broad and dynamic, it is extremely difficult to find time to keep up with the best practices, current research, and innovative ideas. In an effort to help readers keep up their knowledge of the field and to determine some of the most interesting and useful resources to date, a large body of…
ERIC Educational Resources Information Center
Jackson, Bernedette S.
2017-01-01
Learning a second or foreign language may be a daunting task for anyone; however, learning a language that is vastly different from a person's native language can be extremely difficult. This is especially true in South Korea where English is taught and spoken as a foreign language. For Korean students, who typically study English from a young…
ERIC Educational Resources Information Center
Varea, Valeria; Underwood, Mair
2016-01-01
Research among former Physical Education (PE) school students has demonstrated how fat phobia in PE classes is oppressive and makes it extremely difficult for most students to develop positive subjectivities. This study explores how a group of pre-service Health and Physical Education (HPE) specialist teachers from an Australian university…
ERIC Educational Resources Information Center
Cervantes, Joseph M.; Mejia, Olga L.; Mena, Amalia Guerrero
2010-01-01
There has been a significant trend among families from Mexico and Central America to immigrate to the United States due to difficult living conditions, financial hardship, and the lack of opportunity. This article addresses the role of serial migration, where one family member immigrates first and then brings the rest of the family at a later…
Assessing wood quality of borer-infested red oak logs with a resonance acoustic technique
Xiping Wang; Henry E. Stelzer; Jan Wiedenbeck; Patricia K. Lebow; Robert J. Ross
2009-01-01
Large numbers of black oak (Quercus velutina Lam.) and scarlet oak (Quercus coccinea Muenchh.) trees are declining and dying in the Missouri Ozark forest as a result of oak decline. Red oak borer-infested trees produce low-grade logs that become extremely difficult to merchandize as the level of insect attack increases. The objective of this study was to investigate...
1979-05-01
and social problems, does not lend itself to a single or simple solution. This is why we must all be involved. For this reason we. believe that...of admission to decisionmaking. At times the implications of this relatively simple premise are not minor. Many people beginning community...involvement programs have found it extremely difficult to locate technical people able to translate technical reports into simple , every- day English. There
Atmosphere-fire simulation of effects of low-level jets on pyro-convective plume dynamics
Colin C. Simpson; Marwan Katurji; Michael T. Kiefer; Shiyuan Zhong; Joseph J. Charney; Warren E. Heilman; Xindi Bian
2013-01-01
Blow-up fire behaviour can be broadly defined as a rapid escalation in the intensity or forward rate of spread of a wildland fire, and is often accompanied by extreme pyro-convection associated with rapid smoke release and dispersion. Blow-up fire behaviour is difficult to predict and has been linked to firefighter fatalities, making it an important fire management...
Concurrency Attacks and Defenses
2016-10-04
Enter name(s) of person(s) responsible for writing the report, performing the research, or credited with the content of the report. The form of...Amsterdam Avenue New York, NY 10027-7003 Tel.: 212-939-7012 Fax: 212-666-0140 Email : junfeng@cs.columbia.edu 2. Research Objectives...Multithreaded programs are getting increasingly pervasive and critical. Unfortunately, they remain extremely difficult to write . This difficulty has led to
Long-Ming Huang
2000-01-01
Improper cultivation of steep mountainous areas in Taiwan contributes to serious erosion and landslides. Regular patrol, detection, and administration of these problem areas has been an extremely difficult due to the steep and dangerous terrain of many of the forested watersheds in Taiwan. A remotely piloted vehicle (RPV) has been developed for various civil and...
K-wire assisted split-thickness skin graft harvesting from the anterior trunk.
Yontar, Yalcin; Coruh, Atilla; Severcan, Mehmet
2016-02-01
Split thickness skin graft (STSG) harvesting from the anterior chest and abdominal wall skin is quite a difficult process. The main reason for the difficulty to perform this process is the unsuitable anatomic characteristics of the anterior trunk, such as irregular wavy-like surface over the ribs and lax abdominal wall skin resulting in collapse due to lack of adequate underneath supporting structures when a downward force is applied by the skin graft dermatome. Lower extremity and especially the thigh are generally chosen as the donor site where the STSGs are easily harvested from. However, extensive lower extremity burns, with or without other region burns, preclude harvesting auto STSGs from this invaluable anatomic site. We harvested K-wire assisted STSGs from the anterior chest and abdominal wall skin of 7 patients with lower extremity burns and also a patient that sustained motor vehicle collision. We encountered no problems in any of our patients both intra and postoperatively by using K-wire assisted STSG harvesting. All of the STSGs donor sites healed uneventfully without complications. In our opinion, K-wire assisted STSG harvesting must always be in the tool-box of any surgeon who deals with extensive burns with or without lower extremity burns and extensive traumas of lower extremities. Copyright © 2015 Elsevier Ltd and ISBI. All rights reserved.
Malinowska, Agnieszka H; van Strien, Arco J; Verboom, Jana; WallisdeVries, Michiel F; Opdam, Paul
2014-01-01
Weather extremes may have strong effects on biodiversity, as known from theoretical and modelling studies. Predicted negative effects of increased weather variation are found only for a few species, mostly plants and birds in empirical studies. Therefore, we investigated correlations between weather variability and patterns in occupancy, local colonisations and local extinctions (metapopulation metrics) across four groups of ectotherms: Odonata, Orthoptera, Lepidoptera, and Reptilia. We analysed data of 134 species on a 1×1 km-grid base, collected in the last 20 years from the Netherlands, combining standardised data and opportunistic data. We applied dynamic site-occupancy models and used the results as input for analyses of (i) trends in distribution patterns, (ii) the effect of temperature on colonisation and persistence probability, and (iii) the effect of years with extreme weather on all the three metapopulation metrics. All groups, except butterflies, showed more positive than negative trends in metapopulation metrics. We did not find evidence that the probability of colonisation or persistence increases with temperature nor that extreme weather events are reflected in higher extinction risks. We could not prove that weather extremes have visible and consistent negative effects on ectothermic species in temperate northern hemisphere. These findings do not confirm the general prediction that increased weather variability imperils biodiversity. We conclude that weather extremes might not be ecologically relevant for the majority of species. Populations might be buffered against weather variation (e.g. by habitat heterogeneity), or other factors might be masking the effects (e.g. availability and quality of habitat). Consequently, we postulate that weather extremes have less, or different, impact in real world metapopulations than theory and models suggest.
Malinowska, Agnieszka H.; van Strien, Arco J.; Verboom, Jana; WallisdeVries, Michiel F.; Opdam, Paul
2014-01-01
Weather extremes may have strong effects on biodiversity, as known from theoretical and modelling studies. Predicted negative effects of increased weather variation are found only for a few species, mostly plants and birds in empirical studies. Therefore, we investigated correlations between weather variability and patterns in occupancy, local colonisations and local extinctions (metapopulation metrics) across four groups of ectotherms: Odonata, Orthoptera, Lepidoptera, and Reptilia. We analysed data of 134 species on a 1×1 km-grid base, collected in the last 20 years from the Netherlands, combining standardised data and opportunistic data. We applied dynamic site-occupancy models and used the results as input for analyses of (i) trends in distribution patterns, (ii) the effect of temperature on colonisation and persistence probability, and (iii) the effect of years with extreme weather on all the three metapopulation metrics. All groups, except butterflies, showed more positive than negative trends in metapopulation metrics. We did not find evidence that the probability of colonisation or persistence increases with temperature nor that extreme weather events are reflected in higher extinction risks. We could not prove that weather extremes have visible and consistent negative effects on ectothermic species in temperate northern hemisphere. These findings do not confirm the general prediction that increased weather variability imperils biodiversity. We conclude that weather extremes might not be ecologically relevant for the majority of species. Populations might be buffered against weather variation (e.g. by habitat heterogeneity), or other factors might be masking the effects (e.g. availability and quality of habitat). Consequently, we postulate that weather extremes have less, or different, impact in real world metapopulations than theory and models suggest. PMID:25330414
Quantifying uncertainties in wind energy assessment
NASA Astrophysics Data System (ADS)
Patlakas, Platon; Galanis, George; Kallos, George
2015-04-01
The constant rise of wind energy production and the subsequent penetration in global energy markets during the last decades resulted in new sites selection with various types of problems. Such problems arise due to the variability and the uncertainty of wind speed. The study of the wind speed distribution lower and upper tail may support the quantification of these uncertainties. Such approaches focused on extreme wind conditions or periods below the energy production threshold are necessary for a better management of operations. Towards this direction, different methodologies are presented for the credible evaluation of potential non-frequent/extreme values for these environmental conditions. The approaches used, take into consideration the structural design of the wind turbines according to their lifespan, the turbine failures, the time needed for repairing as well as the energy production distribution. In this work, a multi-parametric approach for studying extreme wind speed values will be discussed based on tools of Extreme Value Theory. In particular, the study is focused on extreme wind speed return periods and the persistence of no energy production based on a weather modeling system/hind cast/10-year dataset. More specifically, two methods (Annual Maxima and Peaks Over Threshold) were used for the estimation of extreme wind speeds and their recurrence intervals. Additionally, two different methodologies (intensity given duration and duration given intensity, both based on Annual Maxima method) were implied to calculate the extreme events duration, combined with their intensity as well as the event frequency. The obtained results prove that the proposed approaches converge, at least on the main findings, for each case. It is also remarkable that, despite the moderate wind speed climate of the area, several consequent days of no energy production are observed.
Lecina-Diaz, Judit; Alvarez, Albert; Retana, Javier
2014-01-01
Crown fires associated with extreme fire severity are extremely difficult to control. We have assessed fire severity using differenced Normalized Burn Ratio (dNBR) from Landsat imagery in 15 historical wildfires of Pinus halepensis Mill. We have considered a wide range of innovative topographic, fuel and fire behavior variables with the purposes of (1) determining the variables that influence fire severity patterns among fires (considering the 15 wildfires together) and (2) ascertaining whether different variables affect extreme fire severity within the three fire types (topographic, convective and wind-driven fires). The among-fires analysis showed that fires in less arid climates and with steeper slopes had more extreme severity. In less arid conditions there was more crown fuel accumulation and closer forest structures, promoting high vertical and horizontal fuel continuity and extreme fire severity. The analyses carried out for each fire separately (within fires) showed more extreme fire severity in areas in northern aspects, with steeper slopes, with high crown biomass and in climates with more water availability. In northern aspects solar radiation was lower and fuels had less water limitation to growth which, combined with steeper slopes, produced more extreme severity. In topographic fires there was more extreme severity in northern aspects with steeper slopes and in areas with more water availability and high crown biomass; in convection-dominated fires there was also more extreme fire severity in northern aspects with high biomass; while in wind-driven fires there was only a slight interaction between biomass and water availability. This latter pattern could be related to the fact that wind-driven fires spread with high wind speed, which could have minimized the effect of other variables. In the future, and as a consequence of climate change, new zones with high crown biomass accumulated in non-common drought areas will be available to burn as extreme severity wildfires. PMID:24465492
Lecina-Diaz, Judit; Alvarez, Albert; Retana, Javier
2014-01-01
Crown fires associated with extreme fire severity are extremely difficult to control. We have assessed fire severity using differenced Normalized Burn Ratio (dNBR) from Landsat imagery in 15 historical wildfires of Pinus halepensis Mill. We have considered a wide range of innovative topographic, fuel and fire behavior variables with the purposes of (1) determining the variables that influence fire severity patterns among fires (considering the 15 wildfires together) and (2) ascertaining whether different variables affect extreme fire severity within the three fire types (topographic, convective and wind-driven fires). The among-fires analysis showed that fires in less arid climates and with steeper slopes had more extreme severity. In less arid conditions there was more crown fuel accumulation and closer forest structures, promoting high vertical and horizontal fuel continuity and extreme fire severity. The analyses carried out for each fire separately (within fires) showed more extreme fire severity in areas in northern aspects, with steeper slopes, with high crown biomass and in climates with more water availability. In northern aspects solar radiation was lower and fuels had less water limitation to growth which, combined with steeper slopes, produced more extreme severity. In topographic fires there was more extreme severity in northern aspects with steeper slopes and in areas with more water availability and high crown biomass; in convection-dominated fires there was also more extreme fire severity in northern aspects with high biomass; while in wind-driven fires there was only a slight interaction between biomass and water availability. This latter pattern could be related to the fact that wind-driven fires spread with high wind speed, which could have minimized the effect of other variables. In the future, and as a consequence of climate change, new zones with high crown biomass accumulated in non-common drought areas will be available to burn as extreme severity wildfires.
Beyond PSA: are new prostate cancer biomarkers of potential value to New Zealand doctors?
Ng, Lance; Karunasinghe, Nishi; Benjamin, Challaraj S; Ferguson, Lynnette R
2012-04-20
The widespread introduction of prostate-specific antigen (PSA) screening has enhanced the early detection of prostate cancer within New Zealand. However, uncertainties associated with the test make it difficult to confidently differentiate low-risk patients from those that require a definitive diagnostic biopsy. In consequence, the decisions surrounding prostate cancer treatment become extremely difficult. A number of new tests have become available which might have the potential to complement the current PSA screens. We review a number of the best validated of these which provide data that, although currently not available in clinical practice, some of these might have considerable potential to aid diagnosis, prognosis and therapeutic decisions for men with prostate cancer in New Zealand.
NASA Astrophysics Data System (ADS)
Duque, J.
The use of geophysics prospection in hydrogeology is widely used as a way to find groundwater under difficult hydrogeologic potential rocks. The porphyric rocks lay- ered in the northern part of Beja city, are the most unproductive regional aquifer. Usu- ally this aquifer has an upper layer of 5 to 15 meters deep of weathered rock and a second layer build by fractures rock till 30 metres deep. Above this deep the probabil- ity to find groundwater is extremely low. For instance it is a very superficial aquifer that usually accomplish the topographic surface. The water use is essential for human purposes and here are used mainly for human and cattle supply. In order verify the goodness of a geophysic method and at the same time to supply a large farm called Herdade da Apariça, it was performed the geophysical method of Very Low Frequency (VLF-EM) with ABEM (WADI) equipment, in three areas previously defined by inter- pretation of aerial photography, as zones that have relative hydrogeological potential. It was performed a total of 5 profiles with 1970 m. The geophysic prospecting and hydrogeologic research allowed to drill 5 boreholes, being 4 extraction wells and 1 piezometric well. The productivity of the abstraction wells are between 2,000 L/h and 10,000 L/h, which is a very good yield when compared with the other yield values get from wells inside this aquifer. VLF proved in this conditions to be an essential tool to increment the tax success of drilling wells.
Abraham, Leandro; Bromberg, Facundo; Forradellas, Raymundo
2018-04-01
Muscle activation level is currently being captured using impractical and expensive devices which make their use in telemedicine settings extremely difficult. To address this issue, a prototype is presented of a non-invasive, easy-to-install system for the estimation of a discrete level of muscle activation of the biceps muscle from 3D point clouds captured with RGB-D cameras. A methodology is proposed that uses the ensemble of shape functions point cloud descriptor for the geometric characterization of 3D point clouds, together with support vector machines to learn a classifier that, based on this geometric characterization for some points of view of the biceps, provides a model for the estimation of muscle activation for all neighboring points of view. This results in a classifier that is robust to small perturbations in the point of view of the capturing device, greatly simplifying the installation process for end-users. In the discrimination of five levels of effort with values up to the maximum voluntary contraction (MVC) of the biceps muscle (3800 g), the best variant of the proposed methodology achieved mean absolute errors of about 9.21% MVC - an acceptable performance for telemedicine settings where the electric measurement of muscle activation is impractical. The results prove that the correlations between the external geometry of the arm and biceps muscle activation are strong enough to consider computer vision and supervised learning an alternative with great potential for practical applications in tele-physiotherapy. Copyright © 2018 Elsevier Ltd. All rights reserved.
Nomura, Takuo; Kouta, Munetsugu; Shigemori, Kenta; Yoshimoto, Yoshinobu; Sato, Atsushi
2008-05-01
The purpose of this study was to summarize the approaches to behavior modification for exercise from the viewpoint of preventive medicine. Articles were searched according to the particular field of preventive medicine, i.e., primary prevention, secondary prevention, tertiary prevention, and other fields of prevention. In the field of primary prevention for elderly people living at home, many fall prevention programs were found to have been carried out. In these studies, various programs were found to be effective if the exercise proved to be sufficient. Although some approaches were observed to be based on the productive aging theory and social capital, the number of such studies was small. In the field of secondary prevention, illness and functional disorders are prevented from becoming worse. It is therefore important for each individual to exercise by himself/herself and also acquire sufficient self-monitoring skills. Social capital is useful for learning good exercise habits. In the field of tertiary prevention, although exercise therapy is effective for improving physical functions and preventing disease recurrence in patients with chronic disease, some patients nevertheless find it difficult to continue such an exercise therapy. The approaches to behavior modification were extremely effective for patients with chronic disease. In other fields of preventive medicine, daily exercises such stair climbing are effective methods for reducing the risk of chronic disease and such a behavior modification may lead to a considerable public health gain. In the future, further studies with a many lines of evidence should be performed, and approaches based on behavioral science should be established.
PI3-kinase promotes TRPV2 activity independently of channel translocation to the plasma membrane.
Penna, Aubin; Juvin, Véronique; Chemin, Jean; Compan, Vincent; Monet, Michael; Rassendren, François-A
2006-06-01
Cellular or chemical activators for most transient receptor potential channels of the vanilloid subfamily (TRPV) have been identified in recent years. A remarkable exception to this is TRPV2, for which cellular events leading to channel activation are still a matter of debate. Diverse stimuli such as extreme heat or phosphatidylinositol-3 kinase (PI3-kinase) regulated membrane insertion have been shown to promote TRPV2 channel activity. However, some of these results have proved difficult to reproduce and may underlie different gating mechanisms depending on the cell type in which TRPV2 channels are expressed. Here, we show that expression of recombinant TRPV2 can induce cytotoxicity that is directly related to channel activity since it can be prevented by introducing a charge substitution in the pore-forming domain of the channel, or by reducing extracellular calcium. In stably transfected cells, TRPV2 expression results in an outwardly rectifying current that can be recorded at all potentials, and in an increase of resting intracellular calcium concentration that can be partly prevented by serum starvation. Using cytotoxicity as a read-out of channel activity and direct measurements of cell surface expression of TRPV2, we show that inhibition of the PI3-kinase decreases TRPV2 channel activity but does not affect the trafficking of the channel to the plasma membrane. It is concluded that PI3-kinase induces or modulates the activity of recombinant TRPV2 channels; in contrast to the previously proposed mechanism, activation of TRPV2 channels by PI3-kinase is not due to channel translocation to the plasma membrane.
Tartaglione, Anna Maria; Venerosi, Aldina; Calamandrei, Gemma
2016-01-01
The developmental origin of health and disease hypothesis states that adverse fetal and early childhood exposures can predispose to obesity, cardiovascular, and neurodegenerative diseases (NDDs) in adult life. Early exposure to environmental chemicals interferes with developmental programming and induces subclinical alterations that may hesitate in pathophysiology and behavioral deficits at a later life stage. The mechanisms by which perinatal insults lead to altered programming and to disease later in life are still undefined. The long latency between exposure and onset of disease, the difficulty of reconstructing early exposures, and the wealth of factors which the individual is exposed to during the life course make extremely difficult to prove the developmental origin of NDDs in clinical and epidemiological studies. An overview of animal studies assessing the long-term effects of perinatal exposure to different chemicals (heavy metals and pesticides) supports the link between exposure and hallmarks of neurodegeneration at the adult stage. Furthermore, models of maternal immune activation show that brain inflammation in early life may enhance adult vulnerability to environmental toxins, thus supporting the multiple hit hypothesis for NDDs' etiology. The study of prospective animal cohorts may help to unraveling the complex pathophysiology of sporadic NDDs. In vivo models could be a powerful tool to clarify the mechanisms through which different kinds of insults predispose to cell loss in the adult age, to establish a cause-effect relationship between "omic" signatures and disease/dysfunction later in life, and to identify peripheral biomarkers of exposure, effects, and susceptibility, for translation to prospective epidemiological studies.
NASA Astrophysics Data System (ADS)
Fromm, M. D.
2009-12-01
On 7 February 2009, a date known in Australia as “Black Saturday,” the state of Victoria experienced unprecedented fire-weather conditions. Extremes of temperature, wind, and low relative humidity led to explosive fire growth and pyrocumulonimbus (pyroCb) storms that devastated property and caused many deaths. Presently it appears that the atmospheric effect of the pyroCbs might be equally extreme. Biomass burning emissions such as CO and HCN were measured in the stratosphere in unprecedented abundance for more than one month after Black Saturday. Smoke from these blowups was observed at altitudes greater than 20 km well into Austral autumn. The spread of this stratospheric pall extended from the tropics to Antarctica. Here we will show satellite observations that prove the extreme abundance and altitude of the Black Saturday plume. OMI absorbing aerosol index features were traceable for 25 days, and CALIPSO aerosol profiles showed smoke signatures in early April. ACE Imager aerosol extinction profiles reveal that Black Saturday smoke in the stratosphere was advected from its source in southeastern Australia across the Equator into the northern hemisphere.
Evolution of a minimal parallel programming model
Lusk, Ewing; Butler, Ralph; Pieper, Steven C.
2017-04-30
Here, we take a historical approach to our presentation of self-scheduled task parallelism, a programming model with its origins in early irregular and nondeterministic computations encountered in automated theorem proving and logic programming. We show how an extremely simple task model has evolved into a system, asynchronous dynamic load balancing (ADLB), and a scalable implementation capable of supporting sophisticated applications on today’s (and tomorrow’s) largest supercomputers; and we illustrate the use of ADLB with a Green’s function Monte Carlo application, a modern, mature nuclear physics code in production use. Our lesson is that by surrendering a certain amount of generalitymore » and thus applicability, a minimal programming model (in terms of its basic concepts and the size of its application programmer interface) can achieve extreme scalability without introducing complexity.« less
G-Equivalent Acceleration Tolerance in the Eutardigrade Species Hypsibius dujardini
NASA Astrophysics Data System (ADS)
Vasanthan, Tarushika; Alejaldre, Lorea; Hider, Jessica; Patel, Shreya; Husain, Nabiha; Umapathisivam, Bavithra; Stone, Jonathon
2017-01-01
Tardigrades are microscopic organisms renowned for their ability to survive extreme environmental conditions. Tardigrade extreme-tolerance research has centered on the ability to withstand desiccation, low and high temperatures, and high hydrostatic pressure and radiation levels. Tardigrade tolerance to hypergravity, however, has yet to be described. We used the eutardigrade species Hypsibius dujardini to investigate short-term tolerance to g-equivalent accelerations (i.e., mimicking g-forces). Data obtained from specimens centrifuged between 3421g and 16,060g for 1 min inclusively reveal tolerance in an acceleration-dependent relation, with lower survivorship and egg production at higher accelerations. This is the first study to demonstrate tardigrade potential for tolerance to hypergravity and describe expected effects on tardigrade survival and reproduction. These findings will prove to be useful in lithopanspermia research (i.e., viable spread in meteoritic rocks).
Ewald, Julie A; Wheatley, Christopher J; Aebischer, Nicholas J; Moreby, Stephen J; Duffield, Simon J; Crick, Humphrey Q P; Morecroft, Michael B
2015-11-01
Cereal fields are central to balancing food production and environmental health in the face of climate change. Within them, invertebrates provide key ecosystem services. Using 42 years of monitoring data collected in southern England, we investigated the sensitivity and resilience of invertebrates in cereal fields to extreme weather events and examined the effect of long-term changes in temperature, rainfall and pesticide use on invertebrate abundance. Of the 26 invertebrate groups examined, eleven proved sensitive to extreme weather events. Average abundance increased in hot/dry years and decreased in cold/wet years for Araneae, Cicadellidae, adult Heteroptera, Thysanoptera, Braconidae, Enicmus and Lathridiidae. The average abundance of Delphacidae, Cryptophagidae and Mycetophilidae increased in both hot/dry and cold/wet years relative to other years. The abundance of all 10 groups usually returned to their long-term trend within a year after the extreme event. For five of them, sensitivity to cold/wet events was lowest (translating into higher abundances) at locations with a westerly aspect. Some long-term trends in invertebrate abundance correlated with temperature and rainfall, indicating that climate change may affect them. However, pesticide use was more important in explaining the trends, suggesting that reduced pesticide use would mitigate the effects of climate change. © 2015 John Wiley & Sons Ltd.
A Novel Denitrifying Extreme Halophile That Grows in a Simple Mineral Salts Medium
NASA Technical Reports Server (NTRS)
Hochstein, L. I.; Oremland, R. S.; Gherna, R.; Cote, R.; Chang, Sherwood (Technical Monitor)
1995-01-01
An extremely halophilic bacterium (strain CH-1) was isolated from a saltern adjacent to San Francisco Bay. It grew in a mineral salts medium with ammonium and glucose as sole sources of nitrogen and carbon as well as energy, respectively Cells lysed at less than 10% NaCl and growth was most rapid in medium containing 20% NaCl. Cells were pieomorphic ranging from disc to ovoid-shaved and used a variety of carbohydrates as sole carbon sources. the utilization of certain carbon sources was controlled by temperature with some used at 37 degrees but not 45 C. CH-1 grew between 30 degrees and 50 C with the optimum at 45 C in the presence of 20% NaCl. CH-1 contained 2,3-di-O-isoprenyl glcerol diethers and was sensitive to aphidicofin. The major polar lipid was glucosyl-mannosyl-alucosyl diether, which is diagnostic of the Haloarcula. Thus CH-1 is an extreme halophile and a member of this genus. Among the novel characteristics of this organism was its ability to grow anaerobically in synthetic medium when nitrate was present which was only reduced to nitrous oxide. This organism should prove useful for studying denitrification and carbohydrate metabolism in the extreme halophiles; and to be a valuable resource for generic studies.
Kastenbaum, Hannah A; McPherson, Elizabeth W; Murdoch, Geoffrey H; Ozolek, John A
2009-01-01
Conjoined twinning is a rare form of twinning, in which 2 bodies are attached, and is classified according to the anatomic place of attachment. An extremely rare form of conjoined twinning is janiceps conjoined twinning, in which 2 faces are attached but oriented in opposite directions. In this report, we present an unusual and difficult-to-classify case of conjoined male twins with partial duplication of craniofacial, upper oropharyngeal, and cardiac organs. We believe this to be one of the few reported cases of janiceps asymmetrus. We describe in detail the gross and microscopic pathology and offer some insights into the possible embryogenesis and distinction from the other rare form of conjoined twinning with facial duplication, diprosopus.
Extreme Wind, Rain, Storm Surge, and Flooding: Why Hurricane Impacts are Difficult to Forecast?
NASA Astrophysics Data System (ADS)
Chen, S. S.
2017-12-01
The 2017 hurricane season is estimated as one of the costliest in the U.S. history. The damage and devastation caused by Hurricane Harvey in Houston, Irma in Florida, and Maria in Puerto Rico are distinctly different in nature. The complexity of hurricane impacts from extreme wind, rain, storm surge, and flooding presents a major challenge in hurricane forecasting. A detailed comparison of the storm impacts from Harvey, Irma, and Maria will be presented using observations and state-of-the-art new generation coupled atmosphere-wave-ocean hurricane forecast model. The author will also provide an overview on what we can expect in terms of advancement in science and technology that can help improve hurricane impact forecast in the near future.
Zoster-associated segmental paresis in a patient with cervical spinal stenosis.
Kang, Sung-Hee; Song, Ho-Kyung; Jang, Yeon
2013-06-01
Segmental zoster paresis is a rare complication of herpes zoster, characterized by focal motor weakness that does not always present simultaneously with skin lesions. Zoster paresis can be easily confused with other neuromuscular or spinal diseases. This case report describes the case of a 72-year-old woman with herpes zoster and cervical spinal stenosis at the same spinal level, where it was difficult to distinguish segmental zoster paresis from cervical radiculopathy combined with motor neuropathy. Although segmental zoster paresis in the upper extremity is rare, it should be included in the differential diagnosis of segmental pain and weakness in the extremities, especially in older or immunocompromised patients. Correct diagnosis is required, to avoid unnecessary surgery and allow timely antiviral treatment.
NASA Astrophysics Data System (ADS)
Sun, Liang; McKay, Matthew R.
2014-08-01
This paper studies the sum rate performance of a low complexity quantized CSI-based Tomlinson-Harashima (TH) precoding scheme for downlink multiuser MIMO tansmission, employing greedy user selection. The asymptotic distribution of the output signal to interference plus noise ratio of each selected user and the asymptotic sum rate as the number of users K grows large are derived by using extreme value theory. For fixed finite signal to noise ratios and a finite number of transmit antennas $n_T$, we prove that as K grows large, the proposed approach can achieve the optimal sum rate scaling of the MIMO broadcast channel. We also prove that, if we ignore the precoding loss, the average sum rate of this approach converges to the average sum capacity of the MIMO broadcast channel. Our results provide insights into the effect of multiuser interference caused by quantized CSI on the multiuser diversity gain.
Malignant melanoma of the nose.
Souza, S D; Sujata, G
2001-04-01
Invasive tumors containing abnormal melanocvtes are termed ax malignant melanomas. Primary malignant melanomas of the nasal and paranasal cavities are extremely rare. A 65 years old female presented with bleeding from the nose and a gradually increasing mass in the left nostril. Histopathological examination of the specimen showed "poorly differentiated carcinoma" like features. But S-100 staining proved it to be a malignant melanoma. This case is reported here for its rarity. The literature on malignant melanoma is reviewed and the aetiology pathology, diagnostic and therapeutic problems are also discussed.
[Adenocarcinoma of lung cancer with solitary metastasis to the stomach].
Koh, Sung Ae; Lee, Kyung Hee
2014-09-25
Although hematogenous metastasis of cancer to the gastrointestinal track is rare, it sometime has been reported in patients with malignant melanoma and breast cancer. However, it is extremely rare for lung cancer to metastasize to the stomach, not to mention solitary gastric metastasis. Herein, the authors report a case of a 69-year-old man who was initially diagnosed with lung cancer with synchronous primary gastric cancer which proved to be lung cancer with solitary gastric metastasis after the operation.
U. S. Navy Special Operations (1140) Community Diving and Salvage Functional Area
1993-04-01
to $72,000, but were rejected by the Commandant, Marc Island Navy Yard because the costs were too great. Instead, he attempted to use the new, 21,000...throughout Southeast Asia as well as battle damage and recovery operations. This concept proved to be extremely successfu and cost elfectivt.. In theater...mission by contractor personnel and equipment, or Navy sal.vage ships and assets, to provide cost effective and rapid solutions to a variety of salvage
Evolutionary variational-hemivariational inequalities
NASA Astrophysics Data System (ADS)
Carl, Siegfried; Le, Vy K.; Motreanu, Dumitru
2008-09-01
We consider an evolutionary quasilinear hemivariational inequality under constraints represented by some closed and convex subset. Our main goal is to systematically develop the method of sub-supersolution on the basis of which we then prove existence, comparison, compactness and extremality results. The obtained results are applied to a general obstacle problem. We improve the corresponding results in the recent monograph [S. Carl, V.K. Le, DE Motreanu, Nonsmooth Variational Problems and Their Inequalities. Comparison Principles and Applications, Springer Monogr. Math., Springer, New York, 2007].
Stanley, Theodore H; Egan, Talmage D; Van Aken, Hugo
2008-02-01
Dr. Paul Janssen was the founder of Janssen Pharmaceutica and the developer of over 80 pharmaceutical compounds that proved useful in human, botanical, and veterinary medicine. He and his coworkers synthesized the fentanyl family of drugs, many other potent analgesics, droperidol, etomidate, and numerous other important medicines that were extremely useful in psychiatry, parasitology, gastroenterology, cardiology, virology, and immunology. Anesthesiology and medicine as a whole have benefited a great deal from his resourcefulness, creativity, and entrepreneurial spirit.
NASA Astrophysics Data System (ADS)
Conte, Eric D.; Barry, Eugene F.; Rubinstein, Harry
1996-12-01
Certain individuals may be sensitive to specific compounds in comsumer products. It is important to quantify these analytes in food products in order to monitor their intake. Caffeine is one such compound. Determination of caffeine in beverages by spectrophotometric procedures requires an extraction procedure, which can prove time-consuming. Although the corresponding determination by HPLC allows for a direct injection, capillary zone electrophoresis provides several advantages such as extremely low solvent consumption, smaller sample volume requirements, and improved sensitivity.
Geometric constrained variational calculus. II: The second variation (Part I)
NASA Astrophysics Data System (ADS)
Massa, Enrico; Bruno, Danilo; Luria, Gianvittorio; Pagani, Enrico
2016-10-01
Within the geometrical framework developed in [Geometric constrained variational calculus. I: Piecewise smooth extremals, Int. J. Geom. Methods Mod. Phys. 12 (2015) 1550061], the problem of minimality for constrained calculus of variations is analyzed among the class of differentiable curves. A fully covariant representation of the second variation of the action functional, based on a suitable gauge transformation of the Lagrangian, is explicitly worked out. Both necessary and sufficient conditions for minimality are proved, and reinterpreted in terms of Jacobi fields.
COBE looks back to the Big Bang
NASA Technical Reports Server (NTRS)
Mather, John C.
1993-01-01
An overview is presented of NASA-Goddard's Cosmic Background Explorer (COBE), the first NASA satellite designed to observe the primeval explosion of the universe. The spacecraft carries three extremely sensitive IR and microwave instruments designed to measure the faint residual radiation from the Big Bang and to search for the formation of the first galaxies. COBE's far IR absolute spectrophotometer has shown that the Big Bang radiation has a blackbody spectrum, proving that there was no large energy release after the explosion.
Statecharts Via Process Algebra
NASA Technical Reports Server (NTRS)
Luttgen, Gerald; vonderBeeck, Michael; Cleaveland, Rance
1999-01-01
Statecharts is a visual language for specifying the behavior of reactive systems. The Language extends finite-state machines with concepts of hierarchy, concurrency, and priority. Despite its popularity as a design notation for embedded system, precisely defining its semantics has proved extremely challenging. In this paper, a simple process algebra, called Statecharts Process Language (SPL), is presented, which is expressive enough for encoding Statecharts in a structure-preserving and semantic preserving manner. It is establish that the behavioral relation bisimulation, when applied to SPL, preserves Statecharts semantics